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SPONS' 


MECHANICS'  OWN  BOOK 


A  MANUAL 


FOR 


HANDICRAFTSMEN  AND  AMATEURS. 


SECOND   EDITION. 


E.  &  F.  N.  SPON,  125,  STEAND,  LONDON, 

NEW  YORK:  35,  MURRAY  STREET. 
1886. 


T 


D 


LONDON  : 

PRINTED   BY   WILLIAM   CLOWES   AND   SONS,   LIMITED, 

STAJIFCIUD   STREKT  AND    CHAFING   CROSS. 


■j  HE  GETTY  CENTER 
LIBRARY 


INTKODUCTION. 


The  title  of  this  work  almost  suffices  to  indicate  tbe  character  of  tlie  con- 
tents, without  the  aid  of  any  prefatory  explanation.  The  authors  have  no 
new  theories  to  advance,  nor  discoveries  to  relate  :  their  aim  has  been 
rather  to  discuss  from  an  everyday  practical  view  the  various  mechanical 
trades  that  deal  with  the  conversion  of  wood,  metals,  and  stone  into  useful 
objects. 

The  method  of  treatment  of  each  branch  is  scientific,  yet  simple.  First 
in  order  comes  the  raw  material  worked  upon,  its  characters,  variations, 
and  suitability.  Then  the  tools  used  in  working  up  the  material  are 
examined  as  to  the  principles  on  which  their  shape  and  manipulation  are 
based,  including  the  means  adopted  for  keej)ing  them  in  order,  by  grinding, 
tempering,  filing,  setting,  handling,  and  cleaning.  A  third  section,  where 
necessary,  is  devoted  to  explaining  and  illustrating  typical  examples  of  the 
work  to  be  executed  in  the  particular  material  under  notice.  Thus  the  book 
forms  a  complete  guide  to  all  the  ordinary  mechanical  operations ;  and 
whilst  professional  workmen  will  find  in  it  many  suggestions  as  to  the 
direction  in  which  improvements  should  be  aimed  at,  amateur  readers  will 
be  glad  to  avail  themselves  of  the  simple  directions  and  ingenious  devices 
by  which  they  can  in  a  great  degree  overcome  the  disadvantage  of  a  lack  of 
manipulative  skill. 

To  render  the  book  still  more  useful  to  the  emigrant  and  colonist,  who 
often  has  only  his  own  wits  to  depend  on  in  building  and  repairing  his 
home,  several  further  chapters  have  been  added,  dealing  with  the  enclosure, 
approaches,  water  supply,  drainage,  warming,  lighting,  and  ventilation  of  a 
dwelling. 

In  conclusion,  hearty  thanks  are  tendered  to  the  many  specialists  whose 
writings  have  combined  to  give  unusual  value  to  the  book.  It  is  hoped  that 
the  following  list  is  complete  : — 

Sir  J.  Savile  Lumley  on  bronze  casting ;  J.  Richards,  T.  D.  West, 
W.  H.  Cooper,  and  Leander  Clarke  on  iron  founding  and  casting ;  Joshua 
Eose  on  chisels,  and  hammering  iron  plates  ;  Cameron  Knight  on  black- 
smithing  generally  ;  E.  Kirk  on  soldering  and  burning ;  Dr.  Anderson  on 

a  2 


tV  INTRODUCTION. 

woods ;  Eev.  A.  Eigg  and  A.  Cabo  on  carpenters'  tools ;  Grimsliaw  and 
Hodgson  on  saws ;  Henry  Adams  on  joints  in  woodwork ;  E.  J.  Palmer  and 
J.  Cowan  on  dovetailing  and  dowelling;  A.  Yorke,  E.  Luckhurst,  and 
A.  Watkins,  on  rustic  constructions  ;  D.  B.  Adamson  on  veneering ;  T.  J. 
Barnes  on  wood  carving ;  J.  Dalton  on  French  polishing ;  J.  Woodley  on 
brickwork ;  J.  Slater  on  roofing ;  P.  J.  Davies  on  lead  glazing ;  W.  F. 
Smith  on  metal-working  machine  tools  ;  E.  Lock  wood  on  electric  bells  and 
telephones;  E.  W.  Edis  on  paperhaugings ;  Field  on  lighting;  Eldridge  on 
gas-fitting  ;  A.  Walmisley  on  ventilation  ;  Dr.  Pridgin  Teale  on  warming  ; 
Eev.  J.  A.  Eivington  on  fresco  painting ;  W.  E.  Corson  on  stairs ;  and 
E.  Gambler  Bousfield  on  house  construction  in  Canada.  Mention  may  also 
be  made  of  T.  J.  Syer,  1,  Finsbury  Street,  Chiswell  Street,  at  whose  work- 
shops amateurs  can  receive  lessons  in  the  manipulation  of  tools.  Lastly, 
some  acknowledgment  is  due  to  the  following  technical  journals,  whose 
interesting  columns  always  rcjiay  perusal,  viz.  American  Artizan,  American 
Machinist,  Builder,  Building  News,  Cabinet-maker,  Deutsche  Industrie 
Zeitung,  English  Mechanic,  Industrial  World,  Iron  Age,  Plumber  and 
Decorator,  Sanitary  Eecord,  Scientific  American. 

The  Editous. 


CONTENTS. 


Mechanical  Drawing  :  buying  and  keeping  instruments ;  drawing  boards ;  scales  , 
squares  ;  paper ;  mounting  ;  mounting  on  linen  ;  pencilling  ;  erasing  errors  ;  inking  ; 
testing  straight-edge  ;  using  parallel  rules  ;  using  compasses  ;  tints,  dimensions,  and  centre 
lines;  title;  nature  of  drawings;  finishing  a  drawing;  colours;  shading;  colouring 
tracings  ;  removing  drawings  from  the  board ;  mounting  engravings ;  fixing  pencil  draw- 
ings ;  tracing-cloth;  tracing-paper;  transfer-paper;  copying  drawings     .,       pages  1-13 

Casting  and  Founding :  general  outline  of  the  operations.  Brass  mid  Bronze  Casting : 
characters  of  the  various  alloys  employed,  reactions  of  the  metals  on  each  other,  mixing 
the  metals,  effects  of  tempering;  furnaces,  their  construction,  means  of  producing 
draught,  fuel,  the  ordinary  cupola,  the  ordinary  melting  furnace,  the  circular  melting 
furnace,  the  reverberatory  furnace ;  crucibles ;  moulding  ;  facing  the  moulds,  filling  the 
moulds,  moulding  in  wax,  forma  perduta  method,  castings  of  natural  objects  ;  casting, 
pouring  the  metal,  temperature  for  pouring,  escape  of  gases  from  the  mould,  ornaments 
in  relief;  cores;  making  bronze  figures;  using  plaster  patterns,  finishing  the  casting, 
bronzing  its  surface,  Japanese  bronzes,  inlaying  on  bronzes ;  casting  en  cire  perdue,  the 
model,  reproduction  in  wax,  formation  of  the  core,  constructing  the  lanthorn,  retouching 
the  wax  bust,  preparing  the  bust  before  making  the  cope,  formation  of  the  cope,  firing 
'the  block,  the  final  casting  in  bronze.  Iron  Founding :  pattern-making,  cores,  shrinkage, 
'taper ;  tools,  crucibles,  pots,  moulding  flasks,  packing  the  flasks,  clamping  them  ;  casting 
in  sand,  with  and  without  cores  ;  casting  in  loam  ;  forms  of  castings  ;  examining  castings 
as  to  quality  and  soundness ;  shrinkage  of  iron  castings ;  chilling  iron  castings  .,      13-44 

Forging  and  Finishing :  definition  of  the  terms  ;  explanation  of  the  technical  phrases, 
to  make  up  a  stock,  fireirons,  rod,  bar,  plate,  to  take  a  heat,  to  finish  at  one  heat,  to  draw 
down,  to  draw  away,  to  upset,  scarfing,  butt-weld,  tongue-joint,  to  punch,  to  drift  out, 
the  hammerman,  the  tuyere  or  tweer ;  forges  or  hearths ;  anvils  ;  vices  and  tongs  ; 
hammers ;  cutting  tools,  principles  and  practices  in  making  chisels  ;  drilling  and  boring, 
construction  of  drills;  swaging  tools;  surfacing  tools,  filing  up,  cleaning  clogged  files, 
polishing  ;  screw-cutting  tools ;  forging  ;  welding,  wrought  iron,  steel,  steel  to  wrought 
iron;  tempering,  hardening,  softening,  annealing,  the  colour  scale,  case-hardening; 
examples  of  smiths'  work, — making  keys,  bolts,  nuts,  tongs,  hammers,  chisels,  files, 
scrapers,  drifts,  punches,  spanners,  wrenches  ;  adjusting  surfaces  by  hammering ;  red-lead 
joints;  rust  joints ;  riveting       44-90 

Soldering :  solders,  composition  and  characters  of  these  alloys ;  colouring  solders  to 
match  metals.  Burning  or  Autogenous  soldering  :  adaptations  of  the  process,  application 
to  pewter,  brass  castings,  iron  castings,  stove  plates  ;  burning  seams  in  lead ;  the  burning 
machine,  air-vessels,  bellows,  tubes,  jets,  wind  guards.  Cold  soldering :  the  flux,  the 
solder,  application.  Hai-d  soldering  various  metals  and  objects.  Soft  soldering :  the 
solders,  fluxes,  irons,  and  bits  employed,  and  precautions  needed.  Generalities, — including 
blowpipes,  lamps,  mechanical  blowers,  supports,  tools,  braziers'  hearth,  means  of  heating 
the  iron  ;  hints  on  fluxes,  spelter,  commercial  grades  of  solder,  cleaning  impure  solder, 
soldering  zinc  and  galvanized  iron,  soldei'ing  without  an  iron,  soldering  brass  to  platinum. 

a  3 


VI  CONTENTS. 

soldering  brass  wire,  soldering  brass  to  steel,  mending  cracked  bell,  soldering  iron  and 
steel,  soldering  silver,  soldering  glass  to  metal,  soldering  platinum  and  gold,  mending  tin 
saucepans,  soldering  brass,  soldering  pewters  and  compo  pipes,  laying  sheet  lead,  mending 
leaden  pipe,  gas  for  blowpipe  work,  blowpipe  brazing         90-116 

Slieet-metal  working  :  useful  characters  of  sheet  metals.  Striking  out  the  patterns, 
— relations  of  circles,  cones,  cylindrical  tubes.  Tools, — mallet,  cutting  tools,  flattening 
tools,  folding  tools,  forming  tools.  Working  the  metals, — seamless  goods,  bending,  spinning ; 
seamed  goods,  pipes,  cups,  square  boxes,  riveting 116-126 

Carpentry  : — Woods  :  acacia,  ake,  alder,  alerce,  alerse,  apple,  ash,  assegai,  beeches,  birches, 
blackwood,  boxes,  broadleaf,  bunya-bunya,  cedars,  cedar  boom,  cherry,  chestnut,  cypress, 
cypress  pine,  dark  yellow-wood,  deal,  deodar,  dogwoods,  doom  boom,  ebony,  elms, 
eucalyptus,  fir,  greenheart,  gums,  hickories,  hinau,  hinoki,  hornbeam,  horoeka,  horopito, 
ironbark,  ironwood,  jacks,  jaral,  jarrah,  kaiwhiria,  kamahi,  kanyiu,  kauri,  kohe-kohe, 
kohutuhutu,  kohwai,  larches,  lignum-vitje,  locust-tree,  mahoganies,  maire,  maire-taw-hake, 
mako,  mango,  manuka,  maple,  mingi-mingi,  miro,  monoao,  mora,  muskwood,  mutti, 
nageswar,  nanmu,  naugiia,  neem,  neinei,  oaks,  pai-ch'ha,  pear,  persimmon,  pines,  plane, 
pohutukawa,  poon,  poplar,  pukatea,  puriri,  pymma,  pynkado,  rata,  rewa-rewa,  rohun,  rose- 
wood, sabicu,  sal,  satinwood,  sawara,  she-pine,  sissu,  sneezewood,  S23ruces,  stopperwood, 
stringy-bark,  sycamore,  tamanu,  tauekaha,  Tasmanian  myrtle,  tawa,  tawhai,  teak,  titoki, 
toon,  totara,  towai,  tulip,  walnuts,  willow,  yellow-wood,  yew  ;  British  Guiana  woods  ;  Cape, 
Natal,  and  Transvaal  woods  ;  Ceylon  woods  ;  English  woods  ;  Indian  woods  ;  New  Zealand 
woods :  Queensland  woods ;  Straits  Settlements  woods ;  Tasmanian  woods ;  West  Indian 
woods ;  growth  of  wood  ;  felling  ;  squaring ;  features  ;  defects  ;  selecting  ;  classification  ; 
market  forms  ;  seasoning ;  decay  ;  preserving  ;  fireproofing  ;  conversion  ;  shrinkage  ; 
composition  ;  suitability  ;  strength  ;  measuring  ;  prices.  Tools  :  Guiding  tools, — chalk 
line,  rule,  straight-edge,  squares,  spirit  level,  plumb  level,  gauges,  bevels,  mitre-box, 
compasses,  callipers,  trammel,  shooting-board,  bell-centre  punch,  combinations;  Holding 
tools, — pincers,  vices,  clamps  ;  Rasping  tools, — saws  (principles,  qualities,  selecting,  using, 
filing,  setting,  sharpening,  gumming ;  examples  of  teeth  for  cross-cuts,  back-saws,  fleam 
tooth,  buck-saws,  web-saws,  rip-saws,  circular  saws,  baud-saws  ;  jig-saws,  table  for  jig  and 
circular  saws,  home-made  fret-saw) ;  files  (principles,  forms,  using,  sharpening)  ,  Edge- 
tools, — chisels  and  gouges  (principles,  forms,  using),  spokeshaves,  planes  (principles,  forms, 
adjusting,  using),  sharjieniug  methods  (grindstones,  oilstones),  miscellaneous  forms 
(circular  plane,  rounder,  box  scraper,  veneer  scrape]-,  mitre-plane,  combination  filisters, 
adjustable  dado) ;  Boring  tools, — awls,  gimlets,  augers,  bits  and  braces,  drills,  miscella- 
neous (angular  bit  stock,  countersink,  expansion  bit,  boring  machine) ;  Striking  tools, — 
hammers,  mallets ;  Chopping  tools, — axes  and  hatchets  (principles,  using,  form  of  handle, 
form  of  cutting  edge),  adzes  (curvature);  Accessories, — bench,  bench-stops,  holdfasts, 
sawing  rest,  bench-vices ;  nails,  nail-punch,  nail-pullers ;  screws,  screw-driver.  Care  of 
Tools  :  wooden  parts,  iron  parts,  rust  preventives,  rust  removers.  Construction  :  joints, 
definition  of  carpentry  and  joinery,  principles  of  joints,  equal  bearing,  close  jointing, 
strains,  classification  of  joints,  classification  of  fastenings,  lengthening  joints,  strengthening  ■ 
joints,  bearing  joints,  post  and  beam  joints,  strut  joints,  miscellaneous  joints,  fastenings, 
keying,  corner-piecing,  mortising  and  tenoning,  half-lap  joint,  dovetailing,  blind  dovetails, 
mechanical  aids  in  dovetailing,  dowelling,  joining  thin  woods,  glueing,  hinging.  Examples 
of  Construction  :  workshop  appliances, — tool-chest,  carpenters' bench,  grindstone  mount; 
rough  furniture, — steps,  ladders,  cask-cradle,  tables,  seats  (box  stool,  3-legged  stool, 
chairs),  washstand,  bedstead,  chest  of  drawers,  dresser ;  garden  and  yard  accessories, — 
wheelbarrow,  poultry  and  pigeon  house,  hives,  forcing  frames,  greenhouses,  summer- 
houses,  fences,  gates ;  house  building, — floors,  roofs,  doors,  windows         ..      ..      126-350 

Cabinet-making: — Woods:  Amboyna,  apple,  ash,  beech,  beefwood,  birch,  box,  camphor, 
canary,  cedar,  cherry,  ebony,  holly,  kingwood,  lime,  locust-wood,  mahogany,  maple,  oak, 
partridge-wood,  pear,  pine,  plane,  rose,  sandal,  satin,  teak,  tulip,  walnut,  zebra.     Tools : 


CONTENTS.  Vii 

tool-chest,  bench,  planes,  dowel  plate,  smoothing  implements,  sawinfj  vest,  moulding  board, 
mitring  and  shooting  board,  vice.  Veneering:  cutting  veneers,  fixing  the  veneer  by  the 
hammering  and  cauling  processes,  presses  and  hammers  employed ;  inlaying,  imitation 
inlaying.  Examples :  couch,  chairs,  folding  bookcase,  chest  of  drawers,  wardrobe,  side- 
board               350-386 

Carving  and  Fretwork  : — Carving :  woods, — camphor,  ebony,  lime,  mahogany,  oak, 
pear,  sandal,  sycamore,  walnut,  wild  cherry,  yew  ;  qualities  of  wood,  staining,  adaptability  ; 
tools,  their  selection,  qualities,  use,  sharpening ;  operations.  Fretwork  :  woods ;  tools  ; 
operations 386-399 

XTpllolstery  :  tools  ;  materials  ;  leather  work, — small  chair  buttoned  and  welted,  plain 
seats,  easy  chairs,  settees  and  couches  ;  hair  cloth  ;  fancy  coverings, — plain  seats,  buttoned 
seats,  spring  edges,  French  easy  chairs,  needlework  chairs  ;  mattresses, — spring,  tufted  top, 
folding,  stutled,  French  pallets  ;  beds  and  pillows         399-405 

Painting-,  Graining,  and  Marhling -.—Painting .-  definition  of  paints;  basic 
pigments, — white-lead,  red-lead,  zinc  oxide,  iron  oxide;  colouring  pigments, — blacks,  blues, 
browns,  greens,  lakes,  oranges,  reds,  yellows ;  vehicles  or  mediums, — linseed-oil ;  driers  ; 
grinding;  storing;  applying;  priming;  drying;  filling;  coats;  brushes;  surface; 
removing  old  paint ;  cleaning  painf;  knotting  ;  water-colours ;  removing  smell  ;  discolora- 
tion ;  miscellaneous  paints, — cement  paint  for  carton-pierre,  coloured  paints,  copper  paint, 
floor  painting,  gold  paint,  iron  paint,  iron  painting,  lead  paints,  lime  paints,  silicated 
paint,  steatite  paint,  tin-roofing  paint,  transparent  paint,  tungsten  paints,  window  paint, 
zinc  painting  ;  composition  of  paints  ;  measuring  painters'  work  ;  painters'  cream  ;  wall 
painting,  frescoes,  spirit  fresco,  preparing  the  ground,  the  pigments  admissible  for  colour- 
ing, preparation  of  the  colours,  production  of  delicate  tints,  the  fixing  medium  and  its 
application,  unalterable  durability  of  the  finished  work.  Graining  :  object  of  the  process, 
outline  of  the  operations,  colours,  tools  ;  styles  of  graining — ash,  chestnut,  mahogany,  maple, 
oak  (light  and  dark),  rosewood,  satinwood,  walnut ;  hints.  Marbling :  the  production  of 
painted  surfaces  iu  imitation  of  black  and  gold,  black  Bardilla,  Derbyshire  spar,  dove, 
Egyptian  green,  granites,  Italian  jasper,  royal  red,  St.  Ann's,  sienna,  and  verd  antique 
marbles 405-433 

Staining  :  the  staining  of  wood  considered  as  a  substitute  for  painting,  objects  to  be 
attained,  essential  features  to  be  observed  ;  recipes  for  compounding  and  applying  black 
stains,  black-board  washes,  blue  stains,  brown  stains,  ebonizing,  floor  staining,  green 
stains,  grey  stains,  imitating  and  darkening  mahogany,  oak  stains,  purple  stains,  red 
stains,  imitating  satinwood,  violet  stains,  imitating  and  darkening  walnut,  and  yellow 
stains         433-446 

Gilding  :  what  the  process  consists  in ;  leaf  metals ;  composition  and  characters  of  the 
sizes  used  for  attaching  the  leaf;  tools  and  apparatus.  The  operation  of  Dead  gilding, — 
preparing  the  surface  to  receive  the  leaf,  transferring  the  leaf  to  the  surface,  when  to  lay 
it,  making  good  the  blank  spaces,  completing  the  adh  'sion,  sizing  the  surface  ;  modifications 
for  dead  gilding  on  plain  wood,  polished  wood,  cards,  textiles,  painted  and  japanned 
surfaces,  metals,  masonry,  ivory,  and  plaster  of  Paris.  Bright  Gilding — on  transparent 
material,  such  as  glass ;  securing  adhesion  of  the  leaf,  making  fancy  patterns ;  on  opaque 
material 446-449 

Polishing  :  principles.  Marble  polishing :  producing  a  plane  surfoce,  taking  off  the 
rough,  polishing  up,  rendering  brilliant,  filling  flaws  ;  polishing  imitation  marbles.  Metal 
polishing:  the  broad  principles  of  polishing  metallic  surfaces  by  hand,  best  means  of 
conducting  the  operation,  mistaken  notions  to  be  avoided,  running  work  in  the  lathe, 
relative  merits  of  oils  and  water;  Belgian  burnishing  powder  ;  brass-polishes;  burnishing, 
kinds  of  burnishers,  precautions  in  using  the  burnisher,  variations  in  the  tools  and 
methods  adapted  for  plated  goods,  gold  and  silver  leaf  on  wood,  gold  leaf  on  metal ;  leather 


Vlll  CONTENTS. 

gilding ;  engravers'  burnishers ;  clockmakers'  burnishers  ;  burnishing  book  edges,  cutlery, 
pewter,  and  silver ;  making  crocus ;  emery  paper,  emery  paper  pulp,  emery  wheels ; 
friction  polish  ;  german  silver  polish  ;  glaze  wheels  for  finishing  steel ;  polishing  gold  and 
silver  lace ;  an  artificial  grindstone ;  polishing  and  burnishing  iron  and  steel ;  plate 
powders ;  prepared  chalk ;  putty  powder ;  razor  pastes  ;  rottenstone  or  tripoli ;  rouges. 
Wood  polishing:  object  of  the  process,  what  it  consists  in,  the  preliminary  filling  in, 
modes  of  performing  it  and  materials  employed,  smoothing  the  surface,  rubbing  in  linseed- 
oil,  the  foundation  coat  of  polish,  its  importance  and  the  precautions  to  be  observed  in 
applying  it,  the  bodying-in  process,  allowing  to  harden,  putting  on  the  final  polish, 
original  recipe  for  making  the  finishing  polish,  unfavourable  characters  of  the  ingredients, 
attempts  to  improve  by  bleaching  the  lac,  a  new  evil  thus  introduced,  action  of  solvents 
on  the  lac,  meteorological  conditions  to  be  observed  when  polishing,  most  favourable 
range  of  temperature,  state  of  the  weather,  reasons  for  its  influence ;  general  method  of 
wood  polishing  adopted  in  America ;  the  processes  carried  on  in  first-class  piano  factories ; 
collection  of  recipes  for  furniture  creams,  French  polishes,  reviving  fluids,  compounds  for 
darkening  furniture,  wood-fillers,  and  mixtures  for  black  woodwork,  carvings,  antique 
furniture,  fancy  woods,  black  and  gold  work,  white  and  gold  work,  &c. ;  polishing  woods 
in  the  lathe,  modifications  to  suit  hard  and  soft  woods  ;  the  Japanese  lacquer  shiunkei  as  a 
substitute  for  French  polishing       449-472 

Varnish.irig' :  nature  of  varnishes,  points  governing  their  qualities,  objects  in  view  in 
using  varnishes ;  ingredients  of  varnishes  ;  the  principal  resins  and  gums,  their  varnish- 
making  qualifications  ;  solvents  and  their  suitability  ;  driers  and  the  objections  to  them  ; 
kinds  of  varnish  and  their  essential  differences  ;  mixing  varnishes,  white  oil  vai'uishes  or 
spirit  and  turpentine  varnishes  ;  rules  regulating  the  application  of  varnishes ;  recipes  for 
compounding  oil  varnishes  (copal,  amber,  Coburg,  wainscot,  &c.),  spirit  varnishes  (cheap 
oak,  copal,  hard  spirit,  French  polish,  hardwood  lacquer,  bi'ass  lacquer,  &c.),  turpentine 
varnishes,  Brunswick  black,  and  varnish  for  ironwork         472-475 

Meclianical  Movements  :  simple,  compound,  and  perpetual  motion  ;  pulleys,  blocks 
and  tackle,  White's  pulleys,  Spanish  bartons,  mangle-wheel  and  pinion,  fusee-chain  and 
spring-box,  frictional  clutch-box,  other  kinds  of  clutch-box,  throwing  in  and  out  of  gear 
the  speed  motion  in  lathes,  tilt-hammer  motion,  ore-stamper  motion,  reciprocating  rotary 
motion,  continuous  rotary  motion  converted  into  intermittent  rotary  motion,  self-reversing 
motion,  eccentrics,  crank  motions,  cams,  irregular  vibrating  motion,  feed-motion  of 
drilling  machine,  quick  return  crank  motion  of  shaping  machines,  rectilinear  motion  of 
horizontal  bar,  screw  bolt  and  nut,  uniform  reciprocating  rectilinear  motion,  rectilinear 
motion  of  slide,  screw  stamping  press,  screw-cutting  and  slide-lathe  motion,  spooling- 
frame  motion,  micrometer  screw,  Persian  drill,  rack  and  pinion,  cam  between  friction 
rollers  in  a  yoke,  double  rack,  substitute  for  crank,  doubling  length  of  stroke  of  piston- 
rod,  feed-motion  of  planing  machines,  fiddle  drill,  substitute  for  crank,  bell-crank  lever, 
motion  used  in  air-pumps,  Chinese  windlass,  shears  for  cutting  metal  plates,  lazy  tongs, 
toothed  sectors,  drum,  triangular  eccentric,  cam  and  rod,  cam-wheel,  expansion  eccentric, 
rack  and  frame,  band-saw,  toggle-joint  for  punching  machine,  silk  spooling  motion,  crank 
and  fly-wheel,  yoke-bar,  steam-engine  governor,  valve  motion,  bell-crank,  ellipsograph, 
elbow-lever,  pawl  and  elbow-lever,  crank-pin  and  bell -crank,  treadle  and  disc,  centrifugal 
governor  for  steam-engines,  water-wheel  governor,  knee-lever ;  cam,  bar,  and  rod  ;  spiral 
grooved  drum ;  disc,  crank-pin,  and  slotted  connecting-rod ;  slotted  crank,  engine 
governor,  valve  motion  and  reversing  gear,  obtaining  egg-shaped  elliptical  motion,  silk 
spooling  motion,  carpenters'  bench  clamp,  uncoupling  engines,  varying  speed  of  slide  in 
shaping  machines,  reversing  gear  for  single  engine,  diagonal  catch  and  hand-gear, 
disengaging  eccentric-rod,  driving  feed-rolls,  link-motion  valve-gear,  screw  clamp, 
mangle-wheel  and  pinions,  mangle-rack,  rolling  contact,  wheel  and  pinion,  ratchet-wheel, 
worm-wheels,  pin-wheel  and  slotted  pinion,  Geneva  stop,  stops  for  watches,  cog-\"rheels, 
roller  motion  in  wool-combing  machines,  ratchet  and  pawl,  drag-link  motion,  expanding 


CONTENTS.  IX 

pulley,  chain  and  chain  pulley,  lantern-wheel  stops,  transmitted  circular  motion,  inter- 
mittent circular  motion,  tappet-arm  and  ratchet-wheel,  spur-gear  stops,  pawl  and  crown- 
ratchet,  ratchet-wheel  stops,  brake  for  cranes,  dynamometer,  pantograph,  union  coupling, 
anti-friction  bearing,  releasing  sounding-weight,  releasing  hook  in  pile-driving,  centrifugal 
check-hooks,  sprocket-wheel,  differential  movement,  combination  movement,  series  of 
changes  of  velocity  and  direction,  variable  motion,  circular  into  reciprocating  motion, 
Colt's  revolver  movement,  Otis's  safety  stop,  Clayton's  sliding  journal  box,  Pickering's 
governor,  windlass,  rack  and  pinion  for  small  air-pumps,  feeding  sawing  machine,  movable 
head  of  turning  lathe,  toe  and  lifter,  conical  pendulum,  mercurial  compensation  pendulum, 
compound  bar  compensation  pendulum,  watch  regulator,  compensation  balance,  maintaiu- 
ing  power  in  going  barrel,  Harrison's  going  barrel,  parallel  rulei's,  Cavtwright's  parallel 
motion,  piston-rods,  Chinese  windlass,  gyroscope,  Bohnenberger's  machine,  gyroscope 
governor,  drilling  apjiaratus,  see-saws,  helicograph,  spiral  line  on  cylinder,  cycloidal  sur- 
faces, polishing  mirrors.  White's  dynamometer,  edge-runners,  Robert's  friction  proof, 
portable  cramp  drills.  Bowery's  clamp,  tread-wheels,  pendulum  saws,  adjustable  stand 
for  mirrors,  cloth-dressing  machine,  feed-motion  of  Woodworth's  planing  machine,  Russian 
door-shutting  contrivance,  folding  ladder,  self-adjusting  step-ladder,  lit'ting  jack,  jig-saw, 
polishing  lenses,  converting  oscillating  into  rotary  motion,  reciprocating  into  rotary 
motion,  Parsons's  plan  for  same,  four-way  cock,  continuous  circular  into  intermittent 
rectilinear  reciprocating  motion,  repairing  chains,  continuous  circular  into  intermittent 
circular,  Wilson's  4-motion  feed  for  sewing-machines,  Brownell's  crank  motion,  describing 
parabolas,  cyclographs,  describing  pointed  arches,  centrolinead,  Dickson's  device  for  con- 
verting oscillating  into  intermittent  circular  motion,  proportional  compasses,  Buchanan 
and  Righter's  slide-valve  motion,  trunk-engine,  oscillating  piston  engine,  Root's  double 
quadrant  engine,  rotary  engines,  bisecting  gauge,  self-recording  level,  assisting  crank  of 
treadle  motion  over  dead  centres,  continuous  circular  into  rectilinear  reciprocating 
motion,  continuous  circular  into  rocking  motion,  Root's  double  reciprocating  engine, 
Holly's  rotary  engine,  Jonval  turbine,  reciprocating  motion  from  continuous  fall  of  water, 
water-wheels,  Fourneyron  turbine,  Warren's  turbine,  volute  wheel.  Barker  mill,  tumbler, 
Persian  wheel,  water-raising  machines,  Montgolfier's  hydraulic  ram,  D'Ectol's  oscillating 
column,  swing  boat,  lift-pump,  force-pump,  double-acting  pump,  double  lantern-bellows 
pump,  rotary  pumps,  Hiero's  fountain,  diaphragm  forcing  pump,  counter-balance  bucket, 
pulley  and  bucket,  reciprocating  lift,  Fairbairn's  bailing  scoop,  Lansdell's  steam  siphon 
pump,  swinging  gutters,  chain  pumps,  weir  and  scouring  sluice,  balance  pumps,  steam 
hammer,  Hotchkiss's  atmospheric  hammer,  rotary  motion  from  dilferent  temperatures  in 
two  bodies  of  water,  flexible  water  main,  air-pump,  aeolipile  or  Hero's  steam  toy,  Brear's  bilge 
ejector,  gasometer.  Hoard  and  Wiggin's  steam  trap,  Ray's  steam  trap,  wet  gas-meter,  Powers's 
gas  regulator,  dry  gas-meter,  converting  wind  or  water  motion  into  rotary  motion,  common 
windmill,  vertical  windmill,  paddle-wheel,  screw  propeller,  vertical  bucket  paddle-wheel. 
Brown  and  Level's  boat-detaching  hook,  steering  apparatus,  capstan,  lewis,  tongs  for  lifting 
stones,  drawing  and  twisting  in  textile  spinning,  fan  blower,  siphon  pressure  gauge, 
mercurial  barometer,  epicyclic  trains,  Ferguson's  mechanical  paradox,  aneroid  or  Bourdon 
gauge,  Magdeburg  gauge  ;  gearings,  spur-gears,  multiple  gearing,  brush  wheels,  disc 
wheel  and  spur-gear,  worm  and  worm-wheel,  friction  wheels,  elliptical  spur-gears,  inter- 
nally-toothed spur-gear  and  pinion,  uniform  into  variable  rotary  motion,  uniform  and 
varied  rotary  motion,  sun-and-planet  motion,  frictional  grooved  gearing,  bevel  gears  and 
ratchet-wheels,  bevel  gears  and  double  clutch,  mangle  or  star  wheel,  jumping  rotary 
motion,  registering  revolutions,  scroll  gears,  mangle-rack,  doubling  speed  by  gears,  wheel- 
work  in  base  of  capstan,  Hewlett's  adjustable  frictional  gearing,  scroll  gear  and  sliding 
pinion,  Entwisle's  gearing       ..      -.      475-531 

Turning' :  the  operation.  Lathes,  mandrels,  chucks,  poppet-heads,  rests,  supports,  boring 
collars,  true  frames,  self-acting  slide-rest,  poppet-heads  for  self-acting  lathes,  complete 
double-gear  foot-lathe,  single-gear  foot-lathe,  compound  slide-rests  ;  hints  on  lathe  mani- 


X  CONTENTS. 

pulation,  form  of  tools,  shape  of  cutting  edges,  angle  of  holding,  number  of  tools  required, 
screw  cutting,  skilfiilness  with  hand  tools.  Tools:  their  selection.  Metal-turning  tools: 
their  temper,  grinding,  cutting  angles,  typical  examples ;  iron-turning  tools :  common 
roughing  tool,  round  nose,  parting  tool,  knife  tool  for  finishing  edges  and  faces,  boring 
tools  for  hollow  cylinders,  square  nose,  scraping  tool,  spring  tool,  finishing  tools  for 
rounded  work;  brass-turning  tools;  use  of  water  in  turning;  adapting  tools ;  making 
a  grindstone ;  whetting  tools ;  making  milling  tools  for  screw-heads ;  making  centre 
punches  and  drills ;  scribing  block.  Tool-holders  :  the  swivel  tool-holder  and  its  adap- 
tation to  various  needs — e.  g.  planing  under  horizontal  surface  of  a  lathe-bed,  planing 
in  a  limited  space,  clearing  a  proj  ecting  boss,  cutting  a  vertical  slot,  undercutting 
slots  and  clearance  corners,  cutting  square  threads ;  relation  of  the  cutting  and  clearance 
angles  to  the  work  done ;  grinding  the  cutting  edges,  and  means  suitable  therefor ; 
angle-gauges  for  maintaining  correct  forms ;  system  in  running  an  engineering  works ; 
rehardening  cutters ;  forged  tools  superseded ;  general  remarks  on  the  relative  merits 
of  the  swivel  holders;  broad  finishing  and  its  limits.  Drilling  and  boring  tools:  early 
forms  of  the  twist  drill  ;  necessity  for  absolutely  identical  clearance  angles ;  equal  lips 
cannot  be  attained  by  hand  grinding;  experiments  on  the  cutting  angle;  why  common 
drills  run  ;  fixing  standard  shape  and  clearance  for  lips  of  twist  drills  ;  the  grinding  line  ; 
grinding  machines  for  twist  drills  ;  results  of  tests  and  experiments  with  twist  drills. 
Milling  :  range  of  milling  machines ;  milling  cutters ;  faults  of  the  old  system  ;  modern 
milling  cutters — how  they  are  made  and  set  ;  various  forms, — disc,  cylindrical,  circular 
saw-like,  conical,  annular,  and  complex  forms ;  precautions  in  making  large  cutters ; 
cutting  speed  and  power  required.  Wood-turning  tools  :  plain  gouges  and  chisels  ;  turning 
straight  stuff;  feeling  the  work  ;  holding  the  tool ;  flaws  in  tools  ;  selection  of  gouges  and 
chisels,  their  thickness,  angle  of  cutting  edge,  and  shape  of  edge  ;  various  forms  of  round- 
nosed  tool,  and  how  to  make  them  from  worn-out  files ;  fixing  the  tools  in  handles ; 
restoring  the  edges  of  wood-turning  tools 531-561 

Masonry :  Stonework :  durability  of  natural  stones,  conditions  which  affect  it,  chemical 
composition  must  be  considered,  physical  structure  and  its  influence,  average  life  of  various 
building  stones  ;  working  ;  hardness  ;  strength  ;  weight ;  appearance  ;  position  in  quarry 
seasouing ;  natural  beds  ;  destructive  agents, — chemical,  mechanical,  lichens,  molluscs  ; 
examination, — Brard's  test,  acid  test.  Smith's  test;  quarrying;  classification;  granite; 
serpentine  ;  sandstones  ;  limestones, — marble,  compact  limestones,  shelly  limestones,  mag- 
nesian  limestones  ;  preserving, — painting,  silicatising,  other  processes  ;  stonemasons'  tools, — 
saws,  mallets,  chisels  ;  laying  stonework, — rough  rubble,  coursed  rubble,  combined  rubbles, 
ashlar  work  ;  joining  stones;  stone  walls.  Brickwork:  bricks, — classification,  cutters, 
rubbers,  ordinary  buildmg,  underburnt ;  names  and  prices  of  various  kinds  of  brick,  with 
minute  descriptions ;  qualities  of  a  good  building  brick  ;  size;  testing.  Terracotta  blocks, 
joining  them,  their  advantages  and  disadvantages ;  errors  in  using  terracotta  ;  faults  in 
making  it.  Limes  :  rich  or  fat  limes,  poor  limes,  hydraulic  limes,  artificial  hydraulic  limes. 
Sand :  argillaceous,  siliceous,  and  calcareous,  its  characters  and  impurities  ;  washing, 
substitutes.  Mortar  :  its  quality  governed  by  that  of  its  constituents  ;  danger  of  using  fat 
limes  ;  superiority  of  hydraulic  lime  and  cement ;  objects  of  using  sand,  and  conditions  to  be 
observed  ;  choice  of  water  ;  proportions  of  sand  desirable  ;  measuring  the  ingredients  of 
mortar;  mixing  the  mortar  ;  selenitic  mortar  ;  lime  and  cement  mixtures  ;  grout ;  moisture 
essential  to  the  setting  of  mortars.  Bricklayers' tools.  Laying  bricks  :  sizes,  breaking  joint, 
bond  ;  headers,  stretchers,  and  closers  ;  English  and  Flemish  bond;  raking  courses  in  thick 
walls :  keeping  the  work  level  and  plumb  ;  ensuring  adhesion  between  the  brick  and  the 
mortar;  pointing  and  finishing  brickwork, — striking,  tuck  pointing,  weather  joint,  bastard 
tuck,  bastard-tuck  pointing,  evils  and  uselessness  of  the  common  methods  and  descrij)tion  of 
how  it  should  be  done ;  examples  of  first  and  second  courses  of  walls  in  various  styles  of 
bond  ;  hollow  walls  ;  fireplaces.  Concrete  ;  the  materials  composing  it,  their  choice  and 
proportions  ;  mixing ;  laying  moulds  for  constructing  walls  ;  the  cementing  material ;  bulk 


CONTENTS.  Xi 

produced  ;  selenitic  concrete ;  expansion  of  concrete.     Saltpetreing  of  walls — causes   and 
cure.     Damp  walls  and  their  prevention.     Scaffolding  for  bricklayers       ..      ,.      561-604 

Plastering  and  Whitewashing  :  Plastering  -.  materials, — basis  of  plasters,  Portland 
cement,  Parian  or  Keating's  cement,  composition  of  the  several  coats ;  lime,  water,  and 
hair  used  ;  coarse  stuff",  fine  stuff,  plasterei's'  putty,  gauged  stuff;  selenitic  plaster  ;  rough 
cast ;  stucco ;  scagliola  ;  Marezzo  marble  ;  mouldings  and  ornaments  in  plaster  and  papier 
machd  ;  tools ;  lathing ;  laying  and  pricking-up.  Whitewashing,  Calcimining  or  Distemper 
Fainting :  common  whitewash  or  lime  whiting ;  common  colouring,  making  whiting  ; 
white  and  coloured  distemper ;  indoor  operations  on  good  ceilings  ;  a  simple  lime-wash  ; 
a  good  stone-colour  wash  ;  a  waterproof  calcimine  that  bears  washing  ;  re-whiting  an  old 
dirty  ceiling  ;  further  hints  and  recipes  for  milk  distempers  and  whitewashes,.      604-613 

Roofing  :  pitches  of  roofs,  what  decides  them,  and  what  are  generally  adopted  ;  thatching  ; 
shingles  or  shides  ;  felt ;  dachpappe  ;  Willesden  paper ;  slates  ;  tiles  ;  metallic  roofing 

613-627 

Glazing  :  Glass  of  various  kinds  ;  putty,  soft  putty,  to  soften  putty  ;  tools ;  lead  glazing  ; 
special  methods  of  glazing,  not  dependent  on  putty      627-634 

Bell-hanging  :  the  ordinary  domestic  bell  system,  tubes,  wires,  cranks,  gimlet,  bells,  and 
general  directions  ;  electric  bells, — the  battery,  wires,  circuit-closer,  bells,  arrangement  of 
series  ;  systems  with  1  bell  and  1  press  button,  1  bell  and  2  buttons,  2  bells  and  1  button, 
annunciator  system,  double  system,  bell  and  telephone  ;  making  electric  bell, — backboard 
and  cover,  electro-magnet,  bobbins  or  coils,  filling  the  bobbins  with  wire,  putting  the  bell 
together 634-640 

Gas-fitting  :  fixing  brackets  and  pendants,  making  joints,  using  the  tongs      ..     640-642 

Paper-hanging  :  classification  of  wall  papers,  their  characters  and  uses  ;  how  sold ; 
colours  to  avoid ;  papers  for  damp  walls ;  varnishing,  sizing,  painting  and  washing  wall 
papers  ;  wall  papers  considered  as  ornament,  and  rules  as  to  colour,  pattern,  dado,  and 
frieze  ;  pasting,  cutting,  and  hanging  the  paper,  and  precautions  to  be  observed     642-646 

Lighting  :  natural  lighting,  window  area ;  artificial  lighting  by  candles,  oils,  gas,  and 
electricity.  Oil  lamps,  their  principles,  and  the  objects  aimed  at  in  the  various  forms  of 
wick,  burner,  and  regulator.  Gas,  how  supplied,  computing  the-  number  of  burners 
necessary,  advantage  of  a  ventilator,  how  to  turn  off  gas  at  night ;  construction  of 
burners  and  conditions  that  govern  it ;  distribution  of  jets  ;  selection  of  glass  globes  ;  how 
to  utilize  fully  the  luminosity  of  the  gas.  Electric  lighting, — rules  and  regulations  for 
minimizing  risk,  joining  the  wires 646-654 

Ventilating  :  window  ventilators,  Butler's  system,  Arnott's  system,  Morse's  system, 
American  plan  in  large  buildings,  method  at  St.  Thomas's  Hospital,  method  at  Guy's 
Hospital,  Harding's  ventilators,  system  adopted  by  the  Sanitary  Engineering  and  Venti- 
lating Co.,  Boyle's  air-pump  ventilators,  Kershaw's  chimney  cowl 654—658 

Warming  :  conserving  heat,  double  windows ;  radiant  heat  and  hot  air,  their  relative 
position  as  regards  health  ;  open  grates  ;  open  stoves,  economizing  fuel  with  ordinary 
grates;  close  stoves  ;  hot-air  furnaces  ;  hot-water  heating  ;  steam  heating      ..      658-667 

Foundations  :  points  to  be  considered ;  foundations  on  rock,  gravel,  sand,  clay,  firm 
ground  overlying  soft  ground,  soft  ground  of  indefinite  thickness  ;  concrete  ;  fascines  ; 
piling;  footings;  damp  course        667-670 

Roads  and  Bridges :  Roads :  the  original  foot  track,  temporary  roads  in  unmapped 
country,  one  made  across  the  Chenab ;  plank  roads  and  turnouts ;  pavements, — flagging, 
asphalt,  cement  floors.  Bridges, — simple  timber  bridge,  paved  causeway,  boat  bridges, 
travelling  cradles,  rope  bridges,  weighted  beams 670-676 


Xll  CONTENTS. 

Banks,  Hedges,  Ditches,  and  Drains ..     676-677 

Water  Supply  and  Sanitation  :  river  water,  cleansing  ;  spring  water,  filtering ; 
wells,  sinking  in  various  strata,  steiniug,  simple  plan  used  in  India ;  pumps  and  various 
other  methods  of  raising  water  ;  ponds,  cavern  tanks,  artificial  rain  ponds.  Drains  and 
traps. 677-680 

House  Construction :  Log  huts,  building  the  firejilace.  Frame  houses.  Earth  walls. 
Stairs.  Colonial  houses, — jieculiar  conditions  of  building  in  Canada,  Ceylon,  and  India,  to 
suit  the  climatic  requirements        680-688 


SPONS' 


MECHANICS'    OWN   BOOK. 


MECHANICAL  DRAWING.— A  knowledge  of  the  method  of  mating  working 
■drawings,  and  a  capability  of  interpreting  them  correctly  and  with  facility,  are  essential 
qualifications  in  a  mechanic,  as  almost  all  work,  unless  that  of  a  very  simple  character, 
is  first  drawn  to  scale,  and  then  carried  out  in  detail  according  to  the  drawing.  The 
following  observations  on  the  subject  are  mainly  condensed  from  Richards'  '  Workshop 
Manipulation,'  and  the  first  and  second  series  of  Binns'  '  Orthographic  Projection.' 

The  implements  required  by  the  draughtsman  include  drawing-boards,  scales,  squares, 
compasses,  ruling  pens,  pencils,  Indian  ink,  paper,  indiarubber,  and  water-colours. 

Buying  and  Keeping  Instruments. — Persons  with  limited  means  will  find  it  better  to 
procure  good  instruments  separately  of  any  respectable  maker,  W.  Stanley  of  Holborn 
for  instance,  as  they  may  be  able  to  afford  them,  than  to  purchase  a  complete  set  of 
inferior  instruments  in  a  case.  Instruments  may  be  carefully  preserved  by  merely 
rolling  them  up  in  a  piece  of  wash-leather,  leaving  space  between  them  that  they  may 
not  rub  each  other ;  or,  what  is  better,  having  some  loops  sewn  on  the  leather  to  slip  each 
instrument  separately  under. 

Drawing-boards. — You  may  procure  2  drawing-boards,  42  in.  long  and  30  in.  wide,  to 
receive  "  double  elei)hant "  paper.  Have  the  boards  plain,  without  elects,  or  ingenious 
devices  for  fastening  the  paper ;  they  should  be  made  from  thoroughly  seasoned  wood, 
at  least  I J  in.  thick,  as  if  thinner  they  will  not  be  heavy  enough  to  resist  the  thrust  of  the 
T-squares.  The  qualities  a  good  drawing-board  should  possess  are,  an  equal  surface, 
which  should  be  slightly  rounded  from  the  edges  to  the  centre,  in  order  that  the  drawing- 
paper  when  stretched  upon  it  may  present  a  solid  surface ;  and  that  the  edges  should  be 
perfectly  straight,  and  at  right  angles  to  each  other.  With  2  boards,  one  may  be  used 
lor  sketching  and  drawing  details,  which,  if  done  on  the  same  sheet  with  elevations, 
■dirties  the  paper,  and  is  apt  to  lower  the  standard  of  the  finished  drawing  by  what 
may  be  called  bad  association.  Details  and  sketches,  when  made  on  a  separate  sheet, 
should  be  to  a  larger  scale  than  elevations.  By  changing  from  one  scale  to  another,  the 
mind  is  schooled  in  proportion,  and  the  conception  of  sizes  and  dimensions  is  more  apt 
to  follow  the  finished  work  to  which  the  drawings  relate. 

Sades. — In  working  to  regular  scales,  such  as  J,  a,  or  -Jg.  size,  a  good  j^lan  is  to  use  a 
common  rule,  instead  of  a  graduated  scale.  There  is  nothing  more  convenient  for  a 
mechanical  draughtsman  than  to  be  able  to  readily  resolve  dimensions  into  various  scales, 
and  the  use  of  a  common  rule  for  fractional  scales  trains  the  mind,  so  that  computations 
come  naturally,  and  after  a  time  almost  without  effort. 

Sqjiares. — A  plain  T-square,  with  a  parallel  blade  fastened  on  the  side  of  the  head, 
but  not  imbedded  into  it,  is  the  best ;  in  this  way  set  squares  c  an  be  passed  over  the 

B 


2  Mechanical  Drawing. 

head  of  a  T-square  in  working  at  the  edges  of  the  drawing.  It  is  strange  that  a  drawing 
square  should  ever  have  been  made  in  any  other  manner  tlian  this,  and  still  more  strange, 
that  people  will  use  squares  that  do  not  allow  the  set  squares  to  pass  over  the  heads  and 
come  near  to  the  edge  of  the  board.  A  bevel  square  is  often  convenient,  but  should  be 
an  independent  one ;  a  T-square  that  has  a  movable  blade  is  not  suitable  for  general 
use.  Combinations  in  drawing  instruments,  no  matter  what  their  character,  should  be 
avoided.  For  set  squares,  or  triangles,  as  they  are  sometimes  called,  no  material  is  so 
good  as  ebonite ;  such  squares  are  hard,  smooth,  impervious  to  moisture,  and  contrast 
with  the  paper  in  colour ;  besides,  they  wear  longer  than  those  made  of  wood.  For 
instruments,  it  is  best  to  avoid  everything  of  an  elaborate  or  fancy  kind.  Procure 
only  such  instruments  at  first  as  are  really  required,  of  the  best  quality,  and  then  add 
others  as  necessity  may  demand ;  in  this  way,  experience  will  often  suggest  modifications 
of  size  or  arrangement  that  will  add  to  the  convenience  of  a  set. 

Paper. — The    following  table    contains    the    dimensions  of  every  description    of 
English  drawing-paper. 


in.  in. 

Demy 20  by  15 

Medium 22  „  17 

Royal 24  „  19 

Imperial 31  „  21 

Elephant  ..        ..       27  „  23 


Columbier 

Atlas       

Double  Elephant 

Antiquarian     . . 

Emperor 68 


in. 

in. 

34 

by  23 

33 

„  26 

40 

„  26 

52 

„  29 

68 

„  48 

For  making  detail  drawings  an  inferior  paper  is  used,  termed  Cartridge  ;  this 
answers  for  line  drawings,  but  it  will  not  take  colours  or  tints  perfectly.  Continuous 
cartridge  paper  is  also  much  used  for  full-sized  mechanical  details,  and  some  other 
purposes.  It  is  made  uniformly  53  in.  wide,  and  may  be  had  of  any  length  by  the  yard, 
up  to  300  yd.  For  plans  of  considerable  size,  mounted  paper  is  used,  or  the  drawings 
are  afterwards  occasionally  mounted  on  canvas  or  linen. 

Mounting. — In  mounting  sheets  that  are  likely  to  be  removed  and  replaced,  for  the 
purpose  of  modification,  as  working  drawings  generally  are,  they  can  be  fastened  very 
well  by  small  copper  tacks  driven  in  along  the  edges  at  intervals  of  2  in.  or  less.  The 
paper  can  be  very  slightly  dampened  before  fastening  in  this  manner,  and  if  the  opera- 
tion is  carefully  performed  the  paper  will  be  quite  as  smooth  and  convenient  to  work 
upon  as  though  it  were  pasted  down;  the  tacks  can  be  driven  down  so  as  to  be  flush 
with,  or  below  the  surface  of,  the  paper,  and  will  offer  no  obstruction  to  squares.  If  a 
drawing  is  to  be  elaborate,  or  to  remain  long  upon  a  board,  the  paper  should  be  pasted 
down.  To  do  this,  first  prepare  thick  mucilage,  or  what  is  better,  glue,  and  have  it 
ready  at  hand,  with  some  slips  of  absorbent  paper  1  in.  or  so  wide.  Dampen  the  sheet 
on  both  sides  with  a  sponge,  and  then  apply  the  mucilage  along  the  edge,  for  a  width 
of  J-|  in.  It  is  a  matter  of  some  difficulty  to  place  a  .sheet  upon  a  board;  but  if  the 
board  is  set  on  its  edge,  the  paper  can  be  applied  without  assistance.  Then,  by  putting 
the  strips  of  paper  along  the  edge,  and  rubbing  over  them  with  some  smooth  hard 
instrument,  the  edges  of  the  sheet  can  be  pasted  firmly  to  the  board,  the  paper  slips 
taking  up  a  part  of  the  moisture  from  the  edges,  which  are  longest  in  drying.  If  left 
in  this  condition,  the  centre  will  dry  first,  and  the  paper  be  pulled  loose  at  the  edges  by 
contraction  before  the  paste  has  time  to  dry.  It  is  therefore  necessary  to  pass  over  the 
centre  of  the  sheet  with  a  wet  sponge  at  intervals  to  keep  the  paper  slightly  damp  until 
the  edges  adhere  firmly,  when  it  can  be  left  to  dry,  and  will  be  tight  and  smooth.  One 
of  the  most  common  difficulties  in  mounting  sheets  is  in  not  having  the  gum  or  glue 
thick  enough ;  when  thin,  it  will  bo  absorbed  by  the  wood  or  the  paper,  or  is  too  long  in 
drying.  It  should  be  as  thick  as  it  can  be  applied  with  a  brush,  and  made  from  clean 
Arabic  gum,  tragacantb,  or  fine  glue.  Thumb-tacks  are  of  but  little  use  in  mechanical 
drawing  except  for  the  most  temporary  purposes,  and  may  very  well  be  dispensed  with 


Mechanical  Drawing.  3 

altojtether ;   they  injure  the  drawing-boards,  obstruct  the  squares,  and  disfigure  the 
sheets. 

Mounting  on  Linen. — The  linen  or  calico  is  first  stretched  by  tacking  it  tiglitly  on  a 
frame  or  board.  It  is  then  thoroughly  coated  with  strong  size,  and  left  until  nearly  dry. 
The  sheet  of  paper  to  be  mounted  requires  to  be  well  covered  with  paste ;  this  -will  be 
best  if  done  twice,  leaving  the  first  coat  about  10  minutes  to  soak  into  the  paper.  After 
applying  the  second  coat,  place  the  paper  on  the  linen,  and  dab  it  all  over  with  a  clean 
cloth.     Cut  off  when  thoroughly  dry. 

Pencilling. — This  is  the  first  and  the  most  important  operation  in  drawing ;  more 
skill  is  required  to  produce  neat  pencil-work  than  to  ink  in  the  lines  after  the  pencilling 
is  done.  A  beginner,  unless  he  exercises  great  care  in  the  pencil-work  of  a  drawing, 
■will  have  the  disappointment  to  find  the  paper  soon  becoming  dirty,  and  the  pencil  lines 
crossing  each  other  everywhere,  so  as  to  give  the  whole  a  slovenly  appearance.  lie  will 
also,  unless  he  understands  the  nature  of  the  operations  in  which  he  is  engaged,  make 
the  mistake  of  regarding  the  pencil-work  as  an  unimportant  part,  instead  of  constituting, 
as  it  does,  the  main  drawing,  and  thereby  neglect  that  accuracy  •which  alone  can  make 
either  a  good-looking  or  a  valuable  one.  Pencil-work  is  indeed  the  main  operation,  the 
inking  being  merely  to  give  distinctness  and  permanency  to  the  lines.  The  main  thing 
in  pencilling  is  accuracy  of  dimensions  and  stopping  the  lines  where  they  should  ter- 
minate without  crossing  others.  The  best  pencils  only  are  suitable  for  drawing  ;  if  the 
plumbago  (graphite)  is  not  of  the  best  quality,  the  points  require  to  be  continually 
sharpened,  and  the  pencil  is  worn  away  at  a  rate  that  more  than  makes  up  the  difference 
in  cost  between  the  finer  and  cheaper  grades  of  pencils,  to  say  nothing  of  the  effect 
upon  a  drawing.  It  is  common  to  use  a  flat  point  for  drawing  pencils,  but  a  round  one 
will  often  be  found  quite  as  good  if  the  pencils  are  fine,  and  some  convenience  is 
gained  by  a  round  point  for  freehand  use  in  making  rounds  and  fillets.  A  Faber 
pencil,  that  has  detachable  points  which  can  be  set  out  as  they  are  worn  away,  is 
convenient.  For  compasses,  the  lead  points  should  be  cylindrical,  and  fit  into  a  metal 
sheath  without  paper  packing  or  other  contrivance  to  hold  them  ;  and  if  a  draughtsman 
has  instruments  not  arranged  in  this  manner,  he  should  have  them  changed  at  once, 
both  for  convenience  and  economy.  If  the  point  is  intended  for  sketching,  it  la  cut 
equally  from  all  sides,  to  produce  a  perfectly  acute  cone.  If  this  be  used  for  line 
drawing,  the  tip  will  be  easily  broken,  or  otherwise  it  soon  wears  thick ;  thus,  it  is 
much  better  for  line  drawing  to  have  a  thin  flat  point.  The  general  manner  ef  pro- 
ceeding is,  first,  to  cut  the  pencil,  from  2  sides  only,  with  a  long  slope,  so  as  to  produce 
a  kind  of  chisel-end,  and  afterwards  to  cut  the  other  sides  away  only  sufficient  to  be 
able  to  round  the  first  edge  a  little.  A  point  cut  in  the  manner  described  may  be  kept 
ill  good  order  for  some  time  by  pointing  the  lead  upon  a  small  piece  of  fine  sandstone  or 
fine  glass-paper  ;  this  will  be  less  trouble  than  the  continual  application  of  the  knife, 
which  is  always  liable  to  break  the  extreme  edge. 

Erasing  Errors. — To  erase  Cumberland-lead  pencil  marks,  native  or  liottle  india- 
rubber  answers  perfectly.  This,  however,  will  not  entirely  erase  any  kind  of  German 
or  other  manufactured  pencil  marks.  What  is  found  best  for  this  purpose  is  fino  vul- 
canised india-rubber ;  this,  besides  being  a  more  powerful  eraser,  has  also  the  quality  of 
keeping  clean,  as  it  frets  away  with  the  friction  of  rubbing,  and  presents  a  continually 
renewed  surface  to  the  drawing;  the  worn-oft"  particles  produce  a  kind  of  dust,  easily 
swept  away.  Vulcanised  rubber  is  also  extremely  useful  for  cleaning  off  drawings,  as 
it  will  remove  any  ordinary  stain. 

For  erasing  ink  lines,  the  point  of  a  penknife  or  erasing  knife  is  commonly  used,  A 
much  better  means  is  to  employ  a  piece  of  fine  glass-paper,  folded  several  times,  imtil  it 
presents  a  round  edge ;  this  leaves  the  surface  of  the  paper  in  much  better  order  to  draw 
upon  than  it  is  left  from  knife  erasures.  Fine  size  api^lied  with  a  brush  will  be  found 
convenient  to  prevent  colour  running. 

B  2 


4  Mechanical  Drawing. 

To  produce  finished  drawings,  it  is  necessary  that  no  portion  should  be  erased, 
otlierwise  the  colour  applied  will  be  unequal  in  tone;  thus,  when  highly  finished  me- 
clianical  drawings  are  required,  it  is  usual  to  draw  an  original  and  to  copy  it,  as 
mistakes  are  almost  certain  to  occur  in  delineating  any  new  machine.  Where  sufficient 
time  cannot  be  given  to  draw  and  copy,  a  very  good  way  is  to  take  the  surface  off  the 
paper  with  fine  glass-paper  before  commencing  the  drawing ;  if  this  be  done,  the  colour 
will  ilow  equally  over  any  erasure  it  may  be  necessary  to  make  afterwards. 

Where  ink  lines  are  a  little  over  the  intended  mark,  and  it  is  difficult  to  erase  them 
without  disfiguring  other  portions  of  the  drawing,  a  little  Chinese  white  or  flake-white 
mixed  rather  dry,  may  be  applied  with  a  fine  sable-brush;  this  •will  render  a  small 
defect  much  less  perceptible  than  by  erasure. 

Whenever  the  surface  of  the  paper  is  roughened  by  using  the  erasing  knife,  it  should 
be  rubbed  down  with  some  hard  and  perfectly  clean  rounded  instrument. 

Inldnq. — Ink  used  in  drawing  should  always  be  the  best  that  can  be  procured  ;  without 
good  ink  a  draughtsman  is  continually  annoyed  by  an  imperfect  working  of  pens,  and 
the  washing  of  the  lines  if  there  is  shading  to  be  done.  The  quality  of  ink  can  only  be 
determined  by  experiment;  the  perfume  that  it  contains,  or  tin-foil  wrappers  and 
Chinese  labels,  are  no  indication  of  quality ;  not  even  the  price,  unless  it  be  with 
some  first-class  house.  It  is  better  to  waste  a  little  time  in  preparing  ink  slowly 
than  to  be  at  a  continual  trouble  with  pens,  which  will  occur  if  the  ink  is  ground 
too  rapidly  or  on  a  rough  surface.  To  test  ink,  a  few  lines  can  be  drawn  on  the  margin 
of  a  sheet,  noting  the  shade,  how  the  ink  flows  from  the  pen,  and  whether  the 
lines  are  sharp.  Aftt-r  the  lines  have  dried,  cross  them  with  a  wet  brush:  if 
they  wash  readily,  the  ink  is  too  soft ;  if  they  resist  the  water  for  a  time  and 
tlicn  wash  tardily,  the  ink  is  good.  It  cannot  be  expected  that  inks  soluble  in 
water  can  permanently  resist  its  action  after  drying ;  in  fact,  it  is  not  desirable 
tliat  drawing  inks  should  do  so,  for  in  shading,  outlines  should  be  blended  into 
the  tints  whore  the  latter  are  deep,  and  this  can  only  be  effected  by  washing.  Pens  will 
generally  fill  by  capillary  attraction ;  if  not,  they  should  be  made  wet  by  being  dipped 
into  water.  They  should  not  be  put  into  the  mouth  to  wet  them,  as  there  is  danger 
of  poison  from  some  kinds  of  ink,  and  the  habit  is  not  a  neat  one.  In  using  ruling  pens, 
they  should  be  held  nearly  vertical,  leaning  just  enough  to  prevent  them 
from  catcliing  on  the  paper.  Beginners  have  a  tendency  to  hold  pens  at  a  low 
angle,  and  drag  them  on  their  side,  but  this  will  not  produce  clean  sharp  lines,  nor 
allow  the  linos  to  be  made  near  enough  to  the  edges  of  square  blades  or  set 
squares.  The  pen  should  be  held  between  the  thumb  and  first  and  second  fingers, 
the  knuckles  being  bent,  so  that  it  may  be  at  right  angles  with  the  length  of  the  hand. 
The  ink  should  be  rubbed  up  fresh  every  day  upon  a  clean  palette.  Liquid  ink  and 
other  shnilar  preparations  are  generally  failures.  The  ink  should  be  moderately  thick, 
so  that  the  pen  when  slightly  shaken  will  retain  it  ^  in.  up  the  nibs.  The  pen  is  supplied 
by  breathing  between  the  nibs  before  immersion  iu  the  ink,  or  by  means  of  a  small  camel- 
hair  brush ;  the  nibs  will  afterwards  require  to  be  wiped,  to  prevent  the  ink  going  upon 
the  edge  of  the  instrument  to  be  drawn  against.  The  edge  used  to  direct  the  pen  should 
in  no  instance  be  less  than  -j-'g-  in.  in  thickness  :  Jy  in.  is  perhaps  the  best.  If  the  edge 
be  very  thin,  it  is  almost  impossible  to  prevent  the  ink  escaping  upon  it,  with  the  great 
risk  of  its  getting  on  to  the  drawing.  Before  putting  the  pen  away,  it  should  be 
carefully  wiped  between  the  nibs  by  drawing  a  piece  of  folded  paper  through  them 
until  they  are  dry  and  clean. 

AVith  all  forms  of  dotting  pen  a  little  knack  is  required  in  using.  If  straight  lines 
are  to  be  produced,  it  is  advisable  to  lay  a  piece  of  writing  paper  right  up  to  the  place 
where  the  line  is  intended  to  commence.  By  this  means  it  is  readily  discovered  if  the 
pen  is  working  well.  It  also  avoids  a  starting-point  on  the  drawing,  which  very  com- 
monly leaves  a  few  dots  running  into  each  other.     Fur  drawing  circles  with  the  dotting 


Mechanical  Drawing.  5 

pen,  fixed  iu  the  compass,  the  same  precaution  is  necessary.  The  paper  may  bo  pushed 
aside  as  soon  as  it  comes  in  the  way  of  conipktiug  the  circle.  Another  luceaaary  pre- 
caution with  dotting  pens  is  not  to  stop  during  the  production  of  a  line.  In  all  dotting 
pens  the  rowels  have  to  be  made  rather -loose  to  run  freely,  and  by  this  cause  are  liable 
to  wobble ;  to  avoid  this,  the  pen  should  be  held  slightly  obliiiue  to  the  direction  of  the 
line,  so  as  to  run  the  rowel  against  one  nib  only. 

Testing  Straight-edge. — Lay  the  straight-edge  upon  a  stretched  sheet  of  paper,  placing 
weights  upon  it  to  hold  it  firmly  ;  then  draw  a  line  against  the  edge  with  a  needle  in  a 
holder,  or  a  very  fine  hard  pencil,  held  constantly  vertical,  or  at  one  angle  to  the  paper, 
being  careful  to  use  as  light  pressure  as  possible.  If  the  straight-edge  be  then  turned 
over  to  the  reverse  side  of  the  line,  and  a  second  line  be  produced  in  a  similar  manner 
to  the  first,  at  about  ..'^  in.  distance  from  it,  any  inequalities  in  the  edge  will  appear  by 
the  diflerences  of  the  distances  in  various  parts  of  the  lines,  which  may  be  measured 
by  spring  dividers.  Another  method  will  be  found  to  answer  well  if  3  straight-edges 
are  at  hand ;  this  method  is  used  in  making  the  straight-edge.  Two  straight-edges  are 
laid  together  upon  a  flat  surface,  and  the  meeting  edges  examined  to  see  if  they  touch 
in  all  parts,  reversing  them  iu  every  possible  way.  If  these  appear  perfect,  a  third 
straight-edge  is  applied  to  each  of  the  edges  already  tested,  and  if  that  touch  it  in  all 
parts  the  edges  are  all  perfect.  It  may  be  observed  that  the  first  two  examined,  although 
they  touch  perfectly,  may  be  regular  curves  ;  but  if  so,  the  third  edge  applied  will 
detect  the  curvature. 

Using  Parallel  Eule. — One  of  the  rules  is  pressed  down  firmly  with  the  fingers,  while 
the  other  is  moved  by  the  centre  stud  to  the  distances  at  which  parallel  lines  are 
required.  Should  the  bars  not  extend  a  suflicient  distance  for  a  required  parallel  line, 
one  rule  is  held  firmly,  and  the  other  shifted,  alternately,  until  the  distance  is  reached. 

Using  Compasses. — It  is  considered  best  to  place  the  forefinger  upon  the  head,  and  to 
move  the  legs  within  the  second  linger  and  thumb.  Iu  dividing  distances  into  equal 
parts,  it  is  be^t  to  hold  the  dividers  as  much  as  possible  by  the  head  joint,  after  they 
are  set  to  the  required  dimensions ;  as  by  touching  the  legs  they  are  liable  to  change,  if 
the  joint  moves  softly,  as  it  should.  In  dividing  a  line,  it  is  better  to  move  the  dividers 
alternately  above  and  below  the  line  from  each  point  of  division,  than  to  roll  them 
over  continually  iu  one  direction,  as  it  saves  the  shifting  of  the  fingers  on  the  head  of 
the  dividers.  In  taking  off  distances  with  dividers,  it  is  always  better,  first  to  open, 
them  a  little  too  wide,  and  afterwards  close  them  to  the  point  required,  than  set  them  by 
opening. 

Tints,  Dimensions,  and  Centre  Lines. — A  drawing  being  inked  in,  the  next  things  are 
tints,  dimensions,  and  centre  lines.  The  centre  line  should  be  in  red  ink,  and  pass 
through  all  points  of  the  drawing  that  have  an  axial  centre,  or  where  the  work  is  similar 
and  balanced  on  each  side  of  the  line.  This  rule  is  a  little  obscure,  but  will  be  best 
understood  if  studied  in  connection  with  the  drawing. 

Dimension  lines  should  be  in  blue,  but  may  be  in  red.  Where  to  put  them  is  a 
great  point  in  drawing.  To  know  where  dimensions  are  required  involves  a  knowledge 
acquired  by  practice.  The  lines  should  be  fine  and  clear,  leaving  a  space  iu  their  centre 
for  figures  when  there  is  room.  The  distribution  of  centre  lines  and  dimensions  over  a 
drawing  must  be  carefully  studied,  for  the  double  purpose  of  giving  it  a  good  appear- 
ance and  to  avoid  confusion.  Figures  should  be  made  like  printed  numerals ;  they  are 
much  better  understood  by  the  workman,  look  more  artistic,  and  when  once  learned 
require  but  little  if  any  more  time  than  written  figures.  If  the  scale  employed  is  feet 
and  inches,  dimensions  to  3  ft.  should  be  in  inches,  and  above  this  in  feet  and  inches ; 
this  corresponds  to  shop  custom,  and  is  more  comprehensible  to  the  workman,  however 
wrong  it  may  be  according  to  other  standards. 

In  shading  drawings,  be  careful  not  to  use  too  deep  tints,  and  to  put  the  shades 
in  the  right  place.    Many  will  contend,  and  not  without  good  reasons,  that  working 


6  Mechanical  Drawing. 

drawings  require  no  shading;  yet  it  -will  do  no  barm  to  learn  how  and  where  they  can 
be  bhadfd  :  it  is  better  to  omit  the  shading  frnm  choice  than  from  necessity.  Sec- 
tions must,  of  course,  be  shaded — with  lines  is  the  old  custom,  yet  it  is  certainly  a 
tedious  and  useless  one;  sections  with  light  ink  shading  of  different  colours,  to  indicate 
the  kind  of  material,  are  easier  to  make,  and  look  much  better.  By  the  judicious 
arrangement  of  a  drawing,  a  large  share  of  it  may  be  in  sections,  -which  in  almost 
every  case  are  the  best  views  to  work  by.  The  proper  colouring  of  sections  gives 
a  good  appearance  to  a  drawing,  and  makes  it  "stand  out  from  the  paper."  In  sliading 
sections,  leave  a  margin  of  white  between  the  tints  and  the  lines  on  the  upper  and  left- 
liand  sidcH  of  the  section :  this  breaks  the  connection  or  sameness,  and  the  effect  is 
striking  ;  it  separates  the  parts,  and  adds  greatly  to  the  clearness  and  general  appear- 
ance of  a  drawing. 

Cyliiiihical  parts  in  the  plane  of  sections,  such  as  shafts  and  bolts,  should  be  drawn 
full,  and  Iiave  a  "  round  shade,"  which  relieves  the  flat  appearance — a  point  to  bo 
avoided  as  much  as  possible  in  sectional  views. 

Title — The  title  of  a  drawing  is  a  feature  that  has  much  to  do  with  its  appearance, 
and  tlie  iMiprcssion  conveyed  to  the  mind  of  an  observer.  While  it  can  add  nothing  to 
the  real  value  of  a  drawing,  it  is  so  easy  to  make  plain  letters,  that  the  apprentice  is 
urged  to  learn  this  as  soon  as  he  begins  to  draw ;  not  to  make  fancy  letters,  nor  indeed, 
any  kind  except  plain  block  letters,  which  can  be  rapidly  laid  out  and  finished,  and  con- 
sequently emplo}'ed  to  a  greater  extent.  By  drawing  6  parallel  lines,  and  making  5 
spaces,  and  then  crossing  them  with  equidistant  lines,  the  i^oints  and  angles  in  block 
letters  arc  determined  ;  after  a  little  practice,  it  becomes  the  work  of  but  a  few  minutes 
to  put  down  a  title  or  other  matter  on  a  drawing  so  that  it  can  be  seen  and  read  at  a 
glance  in  searching  for  sheets  or  details.  In  the  manufacture  of  machines,  there  are 
usually  so  many  sizes  and  modifications,  that  drawings  should  assist  and  determine  in  a 
large  degree  the  completeness  of  classification  and  record.  For  simplicity  sake  it  is 
well  to  assume  symbols  for  machines  of  diiferent  classes,  consisting  generally  of  tho 
letters  of  (he  alphabet,  qualified  by  a  single  number  as  an  exponent  to  designate  capacity 
or  different  modifications.  Assuming,  in  the  case  of  engine  lathes,  A  to  be  the  symbol 
for  lathes  of  all  sizes,  then  those  of  different  capacity  and  modification  can  be  represented 
in  the  drawings  and  records  as  A',  A",  and  so  on,  requiring  but  2  characters  to  indicate  a 
lathe  of  any  kind.  These  syndools  should  be  marked  in  large  plain  letters  on  the  left-hand 
lower  corner  of  sheets,  so  that  any  one  can  sec  at  a  glance  what  the  drawings  relate  to. 
'VMien  (ho  dimensions  and  symbols  are  added  to  a  drawing,  the  next  thing  is  pattern  or 
catalogue  numbers.  These  should  be  marked  in  prominent,  plain  figures  on  each  piece, 
either  in  red  or  other  colour  that  will  contrast  with  the  general  face  of  the  drawing. 

Katnrr  of  Drawings. — Isometrical  perspective  is  often  useful  in  drawing,  especially 
in  wood  siructures,  when  the  material  is  of  rectangular  section,  and  disijosed  at  right 
angles,  as  in  machine  frames.  One  isometrical  view,  which  can  be  made  nearly  as 
quickly  as  a  true  elevation,  will  show  all  the  parts,  and  may  be  figured  for  dimensions 
tlie  Bame  as  piano  views.  True  perspective,  although  rarely  necessary  in  mechanical 
drawing,  may  be  studied  with  advantage  in  connection  with  geometry;  it  will  often  lead 
to  the  explanation  of  problems  in  isometric  drawing,  and  will  also  assist  in  free-hand 
lines  that  have  sometimes  to  be  made  to  show  parts  of  machinery  oblique  to  the  regular 
planes. 

Geometrical  drawings  consist  of  plans,  elevations,  and  sections ;  plans  being  views  on 
the  top  of  tho  object  in  a  horizontal  plane ;  elevations,  views  on  the  sides  of  the  object 
in  vertical  planes ;  and  sections,  views  taken  on  bisecting  planes,  at  any  angle  through 
an  object. 

Drawings  in  true  elevation  or  in  section  are  based  upon  flat  planes,  and  given 
dimon.sions  parallel  to  the  planes  in  which  the  views  are  taken. 

Two  elevations  taken  at  right  angles  to  each  other  fix  all  points,  and  give  all 


Mechanical  Drawing.  7 

dimensions  of  parts  that  have  their  axis  parallel  to  tho  planes  on  which  the  views  are 
taken  ;  but  when  a  machine  is  complex,  or  when  several  parts  lie  in  the. same  plane,  3 
and  sometimes  4  views  are  required  to  display  all  the  parts  in  a  comprelicnsive  manner. 

Mechanical  drawings  should  be  made  with  reference  to  all  the  processes  that  are 
required  in  the  construction  of  the  work,  and  the  drawings  should  bo  responsible,  not 
only  for  dimensions,  but  for  unnecessary  expense  in  fitting,  forging,  pattern-making, 
moulding,  and  so  on. 

Every  part  laid  down  has  something  to  govern  it  that  may  be  termed  a  "  base  " — 
some  condition  of  function  or  position  which,  if  understood,  will  suggest  size,  shape,  and 
relation  to  other  parts.  By  searching  after  a  base  for  each  and  every  part  and  detail, 
the  draughtsman  proceeds  upon  a  regular  system,  continually  maintaining  a  test  of  what 
is  done. 

Finisliing  a  Drawing. — While  to  finish  a  drawing  without  any  error  or  defect  should 
be  the  draughtsman's  object,  he  should  never  be  in  haste  to  reject  a  damaged  drawing, 
but  sliould  exercise  his  ingenuity  to  see  how  far  injuries  done  to  it  may  be  remedied. 
Never  lose  a  drawing  once  begun  ;  and  since  ijrcvention  is  easier  and  better  than  cure, 
always  work  calmly,  inspect  all  instruments,  hands,  and  sleeves,  that  may  touch  a 
drawing,  before  commencing  an  operation ;  let  the  paper,  instruments,  and  person  be 
kept  clean,  and  when  considerable  time  is  to  be  spent  upon  a  portion  of  the  paper,  let 
the  remainder  be  covered  with  waste  paper,  pasted  to  one  edge  of  the  board.  For  the 
final  cleaning  of  the  drawing,  stale  bread,  or  the  old-fashioned  black  indiarubber,  if  not 
sticky,  is  good;  but,  aside  from  the  carelessness  of  ever  allowing  a  drawing  to  get  very 
dirty,  any  fine  drawing  will  be  injured,  more  or  less,  by  any  means  of  removing  a 
considerable  quantity  of  dirt  from  it.  Another  excellent  means  of  preventing  injuries, 
■which  should  bo  adopted  when  the  drawing  is  worked  upon  only  at  intervals,  is  to 
enclose  the  board,  when  not  in  use,  in  a  bag  of  enamelled  cloth  or  other  fine  material. 

Colours. — For  colouring  drawings,  the  most  soluble,  brilliant,  and  transparent  water- 
colours  are  used  ;  this  particularly  applies  to  plans  and  sections.  The  colour  is  not  so 
much  intended  to  represent  that  of  the  material  to  be  used  in  the  construction,  as  to 
clearly  distinguish  one  material  from  another  employed  on  the  same  work.  The  following 
table  shows  the  colours  most  employed  by  the  profession : — 

Carmine  or  Crimson  Lake       For  brickwork  in  plan  or  section  to  be  executed. 

-r>        .      -Di  fFlintwork,    lead,    or   parts   of    brickwork  to  ba 

Prussian  Blue |     removed  by  alterations. 

Venetian  Red Brickwork  in  elevation. 

Violet  Carmine Granite. 

Eaw  Sienna        English  timber  (not  oak). 

Burnt  Sienna     Oak,  teak. 

Indian  Yellow Fir  timber. 

Indian  Red         Mahogany. 

Sepia Concrete  works,  stone. 

Burnt  Umber      Clay,  earth. 

Payne's  Grey     Cast  iron,  rough  wrought  iron. 

Dark  Cadmium Gun  metal. 

Gamboge Brass. 

Indigo  Wrought  iron  (bright;. 

Indigo,  with  a  little  Lake  Steel  (bright). 

Hooker's  Green Meadow  land. 

Cobalt  Blue        Sky  effects. 

And  some  few  others  occasionally  for  special  purposes. 

In  colouring  plans  of  estates,  the  colours  that  appear  natural  are  mostly  adopted, 
which  may  be  produced  by  combinring  the  above.     Elevations  and  perspective  drawings 


8  Mechanical  Drawing. 

are  also  represented  in  natural  colours,  the  primitive  colours  being  mixed  aud  varied  b^ 
the  judgment  of  the  drauglitsman,  who,  to  produce  the  best  eflfects,  must  be  iu  some 
degree  an  artist. 

Care  should  be  taken  in  making  an  elaborate  drawing,  which  is  to  receive  colour, 
tliat  the  hand  at  no  time  rest  upon  the  surface  of  the  paper,  as  it  is  found  to  leave  a. 
greasiness  difficult  to  remove.  A  piece  of  paper  placed  under  the  hand,  and  if  the  square 
is  not  very  clean,  under  that  also,  will  prevent  this.  Should  the  colours  from  any  cause,, 
work  greasily,  a  little  prepared  ox-gall  may  be  dissolved  iu  the  water  with  which  the 
colours  are  mixed,  and  will  cause  them  to  work  freely. 

Shading. — For  shading,  camel-  or  sable-hair  brushes,  called  softeners,  are  generally 
Tised :  these  have  a  brush  at  each  end  of  the  handle,  one  being  much  larger  than  tlie 
other.  The  manner  of  using  the  softener  for  shading  is,  to  fill  the  smaller  brush  with 
colour,  and  to  thoroughly  moisten  the  larger  one  with  water ;  the  colour  is  then  laid  upon 
the  drawing  with  the  smaller  brush,  to  represent  the  dark  portion  of  the  shade,  and 
immediately  after,  while  the  colour  is  quite  moist,  the  brush  that  is  moistened  with 
water  is  drawn  down  the  edge  intended  to  be  shaded  ofl';  this  brush  is  then  wiped  uponr 
a  cloth  and  drawn  down  the  outer  moist  edge  to  remove  the  surplus  water,  which  will 
leave  the  shade  perfectly  soft.  If  very  dark  shades  are  required,  this  has  to  be  repeated 
when  the  first  is  quite  dry. 

To  tint  large  surfaces,  a  large  camel-hair  brush  is  used,  termed  a  wash-brush.  The 
manner  of  proceeding  is,  first,  to  tilt  the  drawing,  if  practicable,  and  commence  by 
putting  the  colour  on  from  the  upper  left-hand  corner  of  the  surface,  taking  short  strokes- 
the  width  of  the  brush  along  the  top  edge  of  the  space  to  be  coloured,  immediately  fol- 
lowing with  another  line  of  similar  strokes  into  the  moist  edge  of  the  first  line,  and  so 
on  as  far  as  required,  removing  the  last  surplus  colour  with  a  nearly  dry  brush.  The 
theory  of  the  above  is,  that  you  may  perfectly  unite  wet  colour  to  a  moist  edge,  although 
you  cannot  to  a  dry  edge  without  showing  the  juncture.  For  tinting  surfaces,  it  is  well 
always  to  mix  more  than  sufficient  colour  at  first. 

Colouring  Tracings. — It  is  always  best  to  colour  tracings  on  the  back,  as  the  ink  lines 
are  liable  to  be  obliterated  when  the  colour  is  applied.  Mix  the  colours  very  dark,  so 
that  they  may  appear  of  proper  depth  on  the  other  side.  If  ink  or  colour  does  not  ruii 
freely  on  tracing  cloth,  mix  Loth  with  a  little  ox-gall. 

Eemoving  Drawings  from  the  Board. — Make  a  pencil  line  round  the  paper  with  the 
T-square  at  a  suificient  distance  to  clear  the  glued  edge,  and  to  cut  the  paper  with  a 
penknife,  guided  by  a  stout  ruler.  In  no  instance  should  the  edge  of  the  T-square  be 
used  to  cut  by.  A  piece  of  hard  wood  5  in.  thick  by  2  in.  wide,  and  about  the  length 
of  the  paper,  forms  a  useful  rule  for  the  purpose,  and  may  be  had  at  small  cost.  The 
instrument  used  for  cutting  off,  in  any  important  draughtsman's  office,  is  what  is  tenned 
a  stationers'  rule,  which  is  a  piece  of  hard  wood  of  similar  dimensions  to  that  just 
described,  but  with  the  edges  covered  with  brass.  It  is  necessary  to  have  the  edge- 
thick,  to  prevent  the  point  of  the  knife  slipping  over.  Either  of  the  above  rules  will 
also  answer  to  turn  the  edge  of  the  paper  up  against  when  glueing  it  to  the  board. 

Mounting  Ungravings.—  Sti-ain  thin  calico  on  a  frame,  then  carefully  paste  on  the 
engraving  bo  as  to  be  free  from  creases ;  afterwards,  when  dry,  give  2  coats  of  thin  size 
(a  piece  the  size  of  a  small  nut  in  a  small  cupful  of  hot  water  will  be  strong  enough)  ; 
finally,  when  dry,  varnish  with  white  hard  vamish. 

Fencil  Drawings,  to  fix. — Prepare  water-starch,  in  the  manner  of  the  laundress,  of 
such  a  strength  as  to  form  a  jelly  when  cold,  and  then  apply  with  a  broad  camel-hair 
brush,  as  in  varnishing.  The  same  may  be  done  with  thin,  cold  isinglass  water  or  size, 
or  rice  water. 

Tracing-doth. — Varnish  the  cloth  with  Canada  balsam  dissolved  in  turpentine,  to 
which  may  be  added  a  few  drops  of  castor-oil,  but  do  not  add  too  much,  or  it  will  not 
dry.     Try  a  little  piece  first  with  a  small  quantity  of  varnish.     The  kind  of  cloth  to  use 


Mechanical  Drawing.  9 

is  fine  linen ;  do  not  let  the  varnish  be  too  thick.  Sometimes  difficulties  are  encountered 
in  tracing  upon  cloth  or  calico,  especially  in  making  it  take  the  ink.  In  tlio  lirst  place, 
the  tracing  should  be  made  in  a  warm  room,  or  the  cloth  will  expand  and  become  flabby. 
The  excess  of  glaze  may  be  removed  by  rubbing  the  surface  with  a  chamois  leather,  on 
which  a  little  powdered  chalk  has  been  strewn;  but  this  practice  possesses  the 
disadvantage  of  thickening  the  ink,  besides,  it  might  be  added,  of  making  scratches 
which  detract  fiom  the  effect  of  the  tracing.  The  use  of  ox-gall,  wliich  makes  tlie  ink 
"  take,"  has  also  the  disadvantage  of  frequently  making  it  "  run,"  while  it  also  changes 
the  tint  of  the  colours.  The  following  is  the  process  recommended :  Ox-gall  is  filtered 
through  a  filter  paper  arranged  over  a  funnel,  boiled,  and  strained  through  fine  linen, 
which  arrests  the  scum  and  other  impurities.  It  is  then  placed  again  on  the  fire,  and 
powdered  chalk  is  added.  When  the  effervescence  ceases,  the  mixture  is  again  filtered, 
affording  a  bright  colourless  liquid,  if  the  operation  Las  been  carefully  performed.  A 
drop  or  two  may  be  mixed  with  the  Indian  ink.  It  also  has  the  property  of  effacing 
lead-pencil  marks.  When  the  cloth  tracings  have  to  be  heliographed,  raw  sienna  is  also 
added  to  the  ink,  as  this  colour  unites  with  it  most  intimately,  besides  intercepting  the 
greatest  amount  of  light. 

Tracing-paper. — (1)  A  German  invention  has  for  its  object  the  rendering  more  or  less 
transparent  of  paper  used  for  writing  or  drawing,  either  with  ink,  pencil,  or  crayon,  and 
also  to  give  the  paper  such  a  surface  that  such  writing  or  drawing  may  be  completely 
removed  by  washing,  without  in  any  way  injuring  the  paper.  The  object  of  making  the 
paper  translucent  is  that  when  used  in  schools  the  scholars  can  trace  the  copy,  and  thus 
become  proficient  in  the  formation  of  letters  without  the  explanations  usually  necessary ; 
and  it  may  also  bo  used  in  any  place  where  tracings  may  be  required,  as  by  laying  the 
paper  over  the  object  to  be  copied  it  can  be  plainly  seen.  Writing-paper  is  used  by 
preference,  its  preparation  consisting  in  first  saturating  it  with  benzine,  and  then 
immediately  coating  the  paper  with  a  suitable  rapidly-drying  varnish  before  the  benzine 
can  evaporate.  The  application  of  varnish  is  by  preference  made  by  plunging  the  paper 
into  a  bath  of  it,  but  it  may  be  applied  with  a  brush  or  sponge.  The  varnish  is 
prepared  of  the  following  ingredients : — Boiled  bleached  linseed-oil,  20  lb. ;  lead 
shavings,  1  lb. ;  zinc  oxide,  5  lb. ;  Venetian  turpentine,  J  lb.  Mix,  and  boil  8  hours. 
After  cooling,  strain,  and  add  5  lb.  white  copal  and  J  lb.  sandarach.  (2)  The  following 
is  a  capital  method  of  preparing  tracing-paper  for  architectural  or  engineering 
tracings : — Take  common  tissue-  or  cap-paper,  any  size  of  sheet ;  lay  each  sheet  on  a 
flat  surface,  and  sponge  over  (one  side)  with  the  following,  taking  care  not  to  miss  any 
part  of  the  surface  :— Canada  balsam,  2  pints  ;  spirits  of  turpentine,  3  pints  ;  to  which 
add  a  few  drops  of  old  nut-oil ;  a  sponge  is  the  best  instrument  for  applying  the  mixture, 
which  should  be  used  warm.  As  each  sheet  is  prepared,  it  should  be  hung  up  to  dry 
over  2  cords  stretched  tightly  and  parallel,  about  8  in.  apart,  to  prevent  the  lower 
edges  of  the  paper  from  coming  in  contact.  As  soon  as  dry,  the  sheets  should  be 
carefully  rolled  on  straight  and  smooth  wooden  rollers  covered  with  paper,  about  2  in. 
in  diameter.  The  sheets  will  be  dry  when  no  stickiness  can  be  felt.  A  little  practice 
will  enable  any  one  to  make  good  tracing-paper  in  this  way  at  a  moderate  rate.  The 
composition  gives  substance  to  the  tissue-paper.  (3)  You  may  make  paper  sufliciently 
transparent  for  tracing  by  saturating  it  with  spirits  of  turpentine  or  benzoline.  As 
long  as  the  paper  continues  to  be  moistened  with  either  of  these,  you  can  carry  on  your 
tracing ;  when  the  spirit  has  evaporated,  the  paper  will  be  opaque.  Ink  or  water- 
colours  may  be  used  on  the  surface  without  running.  (4)  A  convenient  method  for 
rendering  ordinary  drawing-paper  transparent  for  the  purpose  of  making  tracings,  and 
of  removing  its  transparency,  so  as  to  restore  its  former  appearance  when  the  drawing 
is  completed,  has  been  invented  by  Puscher.  It  consists  in  dissolving  a  given  quantity 
of  castor-oil  in  1,  2,  or  3  volumes  of  absolute  alcohol,  according  to  the  thickness 
of  the  paper,  and  applying  it  by  means  of  a  sponge.     The  alcohol  evaporates  in  a  few 


10  Mechanical  Drawing. 

minutes,  and  the  tracing:-paper  is  dry  and  ready  for  immediate  use.  The  drawing  or 
tracing  can  be  made  either  with  lead-pencil  or  Indian  iuk,  and  the  oil  removed  from  the 
paper  by  immersing  it  in  absolute  alcohol,  thus  restoring  its  original  opacity.  The 
alcohol  employed  in  removing  the  oil  is,  of  course,  preserved  for  diluting  the  oil  used 
in  preparing  the  next  sheet.  (5)  Put  J  oz.  gum-mastic  into  a  bottle  holding  6  oz.  best 
spirits  of  turpentine,  shaking  it  up  day  by  day ;  when  thoroughly  dissolved,  it  is  ready 
for  use.  It  can  be  made  thinner  at  any  time  by  adding  more  turps.  Then  take  some 
sheets  of  the  best  quality  tissue-paper,  open  them,  and  apply  the  mixture  with  a  small 
brush.  Hang  up  to  dry.  (G)  Saturate  ordinary  writing-paper  with  petroleum,  and 
wipe  the  surface  dry.  (7)  Lay  a  sheet  of  tine  white  wove  tissue-paper  on  a  clean  board, 
brush  it  softly  on  both  sides  with  a  solution  of  beeswax  in  spirits  of  turpentine  (say 
about  i  oz.  in  h  pint),  and  hang  to  dry  for  a  few  days  out  of  the  dust. 

Transfer-paper.— {I)  Rub  the  surface  of  thin  post  or  tissue-paper  with  graphite 
(blacklead),  vermilion,  red  chalk,  or  other  pigment,  and  carefully  remove  the  excess  of 
colouring  matter  by  rubbing  with  a  clean  rag.  (2)  Eub  into  thin  white  paper  a 
mixture  of  6  parts  lard  and  1  of  beeswax,  with  sufficient  fine  lampblack  to  give  it  a 
good  colour ;  apply  the  mixture  warm,  and  not  in  excess.  (3)  Under  exactly  the  same 
conditions  use  a  compound  consisting  of  2  oz.  tallow,  J  oz.  powdered  blacklead 
(graphite),  J  pint  linseed  oil,  and  enough  lampblack  to  produce  a  creamy  consistence. 

Copyinrj  Lraidmjs. — Apart  from  the  mechanical  operation  of  tracing,  there  are 
several  methods  by  which  facsimile  copies  of  drawings  can  be  produced  with  a  very 
slight  expenditure  of  labour  and  at  small  cost.  These  will  now  be  described.  (1)  Cyano- 
type,  or  ferro-prussiate  paper.  This  is  prepared  by  covering  one  side  of  the  sheet  with 
a  mixture  of  red  prussiate  of  potash  (potassium  ferrocyanide)  and  iron  peroxide ;  under 
the  influence  of  light,  i.  e.  mider  the  white  portions  of  the  drawing  to  be  copied,  the 
ferric  compound  is  reduced  to  the  state  of  a  ferrous  salt,  which  gives  with  the  red 
prussiate  of  potasli  an  intense  blue  coloration,  analogous  to  Prussian  blue.  This 
coloration  is  not  produced  in  the  portions  of  the  sensitive  paper  protected  from  the 
light  by  the  black  lines  of  the  drawing  to  be  copied,  and  on  washing  the  print  the 
design  appears  in  white  lines  on  a  blue  ground.  The  formula  for  preparing  the  sensitive 
paper  is  as  follows: — Dissolve  10  dr.  red  prussiate  of  potash  (ferrocyanide)  in  4  oz. 
water;  dissolve  separately  15  dr.  ammonio-citrate  of  iron  in  4  oz.  water;  filter  the 
2  solutions  through  ordinary  filtering-paper,  and  mix.  Filter  again  into  a  large  flat 
dish,  and  float  each  sheet  of  paper  to  be  sensitised  for  2  minutes  on  the  surface  of  the 
liquid,  without  allowing  any  of  this  to  run  over  the  back  of  the  paper.  Hang  up  the 
sheets  in  a  dark  place  to  dry,  and  keep  from  light  and  dampness  until  used.  They  will 
retain  sensitiveness  for  a  long  time.  The  paper  being  ready,  the  copy  is  easily  made. 
Procure  either  a  heavy  sheet  of  plate  glass,  or  a  photographer's  printing  frame,  and  lay 
the  drawing  to  be  copied  with  the  face  against  the  glass ;  on  the  back  of  the  drawing, 
lay  the  prepared  side  of  the  sensitive  pajDcr,  place  upon  it  a  piece  of  thick  felt,  and 
replace  the  cover  of  the  printing  frame,  or  in  some  other  way  press  the  felt  and  papers 
firmly  against  the  glass.  Expose,  glass  side  up,  to  sunshine  or  difi"used  daylight,  for  a 
time,  varying,  with  the  intensity  of  the  light  and  the  thickness  of  the  paper  bearing  the 
original  drawing,  from  minutes  to  hours.  It  is  better  to  give  too  much  than  too  little 
exposure,  as  the  colour  of  a  dark  impression  can  be  reduced  by  long  washing,  whUe  a 
feeble  print  is  irremediably  spoiled.  By  leaving  a  bit  of  the  sensitive  paper  projecting 
from  under  the  glass,  the  progress  of  the  coloration  can  be  observed.  When  the  ex- 
posure has  continued  long  enough,  the  frame  is  opened  and  the  sensitive  sheet  is  with-  v 
drawn  and  thrown  into  a  pan  of  water,  to  be  replaced  immediately  by  another,  if  several 
copies  are  desired,  so  that  the  exposure  of  the  second  may  be  in  progress  while  the  first 
is  being  washed  and  fixed.  The  water  dissolves  out  the  excess  of  the  reagents  used  in 
the  preparation  of  the  paper,  and  after  several  washings  with  fresh  water  the  print 
loses  its  sensitiveness  and  becomes  permanent.    It  is  advantageous,  after  several  washings 


Mechanical  Drawing.  11 

witli  water,  to  pass  over  the  wet  surface  a  weak  solution  of  chlorine  or  of  hydrochloric 
acid,  3  or  4  parts  acid  to  100  of  water,  which  gives  brilliancy  and  solidity  to  tlie  blue 
tint,  and  prevents  it  Ironi  being  washed  out  by  long  soaking.  This  should  be  followed 
by  2  or  3  rinsings  witli  fresh  water,  and  the  print  may  then  be  hung  up  to  dry,  or  placed 
between  sheets  of  bkjtting-paper.  This  mode  of  reproduction,  whose  simplicity  lias  led 
to  its  adoption  in  many  offices,  has  the  inconvenience  of  giving  a  copy  in  white  lines  on 
blue  ground,  which  fatigues  the  eye  in  some  cases,  while  the  application  of  other  colours 
is  impracticable.  By  repeating  and  reversing  the  process,  copying  the  white  line  print 
first  obtained  on  another  sensitive  sheet,  a  positive  picture,  representing  the  black  lines 
of  the  original  by  blue  lines  on  white  ground,  can  be  obtained;  or  the  same  result  may 
be  reached  by  a  different  mode  of  treating  the  sensitive  paper.  Tliis  latter  may  also  be 
made  by  brushing  it  over  with  a  solution  of  ferric  oxalate  (10  gr.  to  the  oz.)  ;  the  ferric 
oxalate  is  prepared  by  saturating  a  hot  aqueous  solution  of  oxalic  acid  with  ferric  oxide. 
A  better  sensitising  solution  may  be  made  by  mixing  437  gr.  ammonium  oxalate,  386  gr. 
oxalic  acid,  and  6  oz.  water,  heating  to  boiling-point,  and  stirring  in  as  much  hydrated 
iron  peroxide  as  it  will  dissolve. 

(2)  Several  varieties  of  paper  called  "  cyanoferric,"  or  "  gommoferric,"  are  sold, 
which  have  the  property  of  giving  a  positive  image.  The  mode  of  preparation  is  nearly 
the  same  for  all:  3  solutions,  1  of  60  oz.  gum  arabic  in  300  of  water;  1  of  40  oz.  ammo- 
niacal  citrate  of  iron  in  80  of  water;  .1  of  25  oz.  iron  perchloride  in  50  of  water,  are 
allowed  to  settle  untd  clear,  then  decanted,  mixed,  and  poured  into  a  shallow  dish,  the 
sheets  being  floated  on  the  surface  as  before,  and  hung  up  to  dry.  The  solution  soon 
becomes  turbid,  and  must  be  used  immediately ;  but  the  paper  once  dry  is  not  subject  to 
change,  unless  exposed  to  light  cr  moisture.  The  reactions  involved  in  the  printing 
process  are  more  complex  than  in  the  first  process,  but  present  no  particular  difficulty. 
Under  the  influence  of  light  and  of  the  organic  acid  (citric),  the  iron  perchloride  is  re- 
duced to  protochloride,  and,  on  being  subjected  to  the  action  of  potassium  ferrocyauide, 
the  portions  not  reduced  by  the  action  of  the  light,  that  is,  the  lines  corresponding  to  the 
black  lines  of  the  original  drawing,  alone  exhibit  the  blue  coloration.  The  gum  plays 
also  an  important  part  in  the  process  by  becoming  less  soluble  in  the  parts  exposed  to 
light,  so  as  to  repel  in  those  portions  the  ferrocyanide  solution.  The  mode  of  printing 
is  exactly  the  same  as  before,  but  the  paper  is  more  sensitive,  and  the  exposure  varies 
from  a  few  seconds  in  sunshine  to  15  or  20  minutes  in  the  shade.  The  exact  period 
must  be  tested  by  exposing  at  the  same  time  a  slip  of  the  sensitive  paper  under  a  piece 
of  paper  similar  to  that  on  which  the  original  drawing  is  executed,  and  ruled  with  fine 
lines,  so  that  bits  can  be  torn  off  at  intervals,  and  tested  in  the  developing  bath  of 
iwtassium  ferrocyanide.  If  the  exposure  is  incomplete,  the  paper  will  become  blue  all 
over  in  the  ferrocyanide  bath  ;  if  it  has  been  too  prolonged,  uo  blue  whatever  will  make 
its  appearance,  but  the  paper  will  remain  white ;  if  it  is  just  long  enough,  the  lines 
alone  will  be  developed  in  blue  on  a  white  ground.  During  the  tests  of  the  trial  bits, 
the  printing  frame  should  be  covered  with  an  opaque  screen  to  prevent  the  exposure 
from  proceeding  further.  After  the  exact  point  is  reached,  the  print  is  removed  from 
the  frame  and  floated  for  a  few  moments  on  a  bath  of  saturated  solution  of  potassium 
ferrocyanide,  about  1  oz.  of  the  solid  crystals  to  4  of  water.  On  raising  it,  the  design 
will  be  seen  in  dark-blue  lines  on  white  ground.  It  is  necessary  to  prevent  the  liquid 
from  flowing  over  the  back  of  the  paper,  which  it  would  cover  with  a  blue  stain,  and  to 
prevent  this  the  edges  of  the  print  are  turned  up  all  round.  On  lifting  a  corner,  the 
progress  of  the  development  may  be  watched.  As  soon  as  the  lines  are  sufficiently  dark, 
or  blue  specks  begin  to  show  themselves  in  the  white  parts,  the  process  must  be  imme- 
diately arrested  by  placing  the  sheet  on  a  bath  of  pure  water.  If,  as  often  happens,  a 
blue  tint  then  begins  to  spread  all  over  the'  paper,  it  may  be  immersed  in  a  mixture  of 
3  parts  sulphuric  or  8  of  hydrochloric  acid,  to  100  of  water.  After  leaving  it  in  this 
acidulated  liquid  for  10  or  15  minutes,  the  design  will  seem  to  clear,  and  the  sheet  may 


12  Mechanical  Drawing. 

then  be  rinsed  in  a  large  basin  of  water,  or  under  a  faucet  furnished  with  a  sprinkling 
nozzle,  and  a  soft  brush  u«ed  to  clour  away  any  remaining  cloudd  of  blue ;  and  finally, 
the  paper  hung  up  to  dry.  Tl;e  ferrocyanide  bath  is  not  subject  to  change,  and  may 
be  used  to  the  last.  If  it  begins  to  crystallise  by  evaporation,  a  few  drops  of  water  may 
be  added.  The  specks  of  blue  which  are  formed  in  this  bath,  if  not  removed  by  tlic 
subsequent  washings,  may  be  taken  out  at  any  time  by  touching  them  with  a  weak 
solution  of  soda  or  potash  carbonate.     The  prints  may  be  coloured  in  the  usual  way. 

(8)  Blue  figures  on  a  white  ground  arc  changed  into  black  by  dipping  the  proof  in  a 
solution  of  i  oz.  common  potash  in  100  oz.  water,  when  the  blue  colour  gives  place  to  a 
sort  of  rusty  colour,  produced  by  iron  oxide.  The  proof  is  then  dipped  in  a  solution  of 
5  oz.  tannin  in  100  oz.  water.  The  iron  oxide  takes  up  the  tannin,  changing  to  a  deep 
black  colour ;  this  is  fixed  by  washing  in  pure  water. 

(4)  Joltrain's.  Black  lines  on  white  ground.  The  paper  is  immersed  in  the  following 
solution:— 25  oz.  gum,  3  oz.  sodium  chloride,  10  oz.  iron  perchloride  (45°  B.),  5  oz.  iron 
sulphate,  4  oz.  tartaric  acid,  47  oz.  water.  The  developing  bath  is  a  solution  of  red  or 
yellow  prussiute  of  potash,  neutral,  alkaline,  or  acid.  After  being  exposed,  the  positive 
is  dipped  in  this  bath,  and  the  parts  which  did  not  receive  the  light  take  a  dark-green 
colour  ;  the  other  parts  do  not  change.  It  is  then  washed  with  water  in  order  to  remove 
the  excess  of  prussiate,  and  dipped  in  a  bath  containing  acetic,  hydrochloric,  or  sulphuric 
acid,  when  all  the  substances  which  could  afi'ect  the  whiteness  of  the  paper  are  removed. 
The  lines  have  now  an  indigo-black  colour.     Wash  in  water,  and  dry. 

(5)  Copies  of  drawings  or  designs  in  black  and  white  may  be  produced  upon  paper 
and  linen  by  giving  the  surface  of  the  latter  2  coatings  of:  217  gr.  gum  arable,  70  gr. 
citric  acid,  135  gr.  iron  chloride,  J  pint  water.  The  prej^ared  material  is  printed  under 
the  drawing,  and  then  immersed  in  a  bath  of  yellow  prussiate  of  potash,  or  of  silver 
nitrate,  the  picture  thus  developed  being  afterwards  put  in  water  slightly  acidified  with 
sulphuric  or  hydrochloric  acid. 

(G)  Bcnneden  states  that  paper,  prepared  as  follows,  costs  but  ^  as  much  as  the 
ordinary  silver  chloride  paper,  is  as  well  adapted  to  the  multiplication  of  drawings,  and 
is  simpler  in  its  manipulation.  A  solution  of  potash  bichromate  and  albumen  or  gum, 
to  which  carbon,  or  some  pigment  of  any  desired  shade,  has  been  added,  is  brushed,  as 
uniformly  as  possible,  upon  well-sized  paper  by  lamplight,  and  the  paper  is  dried  in  the 
dark.  The  drawing,  executed  on  fine  transparent  paper  (or  an  engraving,  or  woodcut, 
&c.),  is  tlien  jdaccd  beneath  a  flat  glass  upon  the  prepared  paper,  and  exposed  to  the 
light  for  a  length  of  time  dependent  upon  the  intensity  of  the  light.  Tlio  drawing  is 
removed  from  the  paper  by  lamidight,  and  after  washing  the  latter  with  water,  a  negative 
of  the  drawing  remains,  since  the  portions  of  the  coating  acted  on  by  the  light  become 
insoluble  in  water.  Fjom  such  a  negative,  any  number  of  positives  can  be  taken  in  the 
same  way. 

(7)  Dieterich's  copying-paper.  The  manufacture  may  be  divided  into  2  parts,  viz. 
the  production  of  the  colour  and  its  application  to  the  paper.  For  blue  paper,  he  uses 
Paris  blue,  as  covering  better  than  any  other  mineral  colours.  10  lb.  of  this  colour  are 
coarsely  powdered,  and  mixed  with  20  lb.  ordinary  olive  oil;  |  lb.  glycerine  is  then 
added.  This  mixture  is,  for  a  week,  exposed  in  a  drying-room  to  a  temperature  of 
104°-122°  F.  (IC^-^O"  C.)  and  then  ground  as  fine  as  possible  in  a  paint-mill.  The 
glycerine  softens  the  liard  paint,  and  tends  to  make  it  more  easily  diffusible.  Melt 
i  lb.  yellow  wax  with  18|  lb.  ligroine,  and  add  to  this  7^  lb.  of  the  blue  mixture, 
mixing  slowly  at  a  temperature  of  SG°-104°  F.  (30°-40°  C).  The  mass  is  now  of  the 
consistence  of  honey.  It  is  applied  to  the  paper  with  a  coarse  brush,  and  afterward 
evenly  divided  and  polished  with  a  badgers'  hair  brush.  The  sheets  are  then  dried  on  a 
table  heated  by  steam.  This  is  done  in  a  few  minutes,  and  the  paper  is  then  ready  for 
the  market.  The  quantities  mentioned  will  be  sutficient  for  about  1000  sheets  of  3G  in. 
by  20,  being  a  day's  work  for  2  girls.     For  black  paper,  aniline  black  is  used  in  the  same 


Casting  and  Founding.  13 

proportion.  The  operation  must  bo  carried  on  in  well-vcntilatcd  rooms  protected  from 
tire,  on  account  of  the  combustibility  of  the  material  and  the  narcotic  eft'eeta  of  the 
ligroine.  The  paper  is  used  between  2  sheets  of  paper,  the  upper  receiving  tlio  original 
the  lower  the  copy. 

(8)  By  means  of  gelatine  sensitive  paper  any  ordinary  thick  cardboard  drawing  can 
be  copied  in  a  few  seconds,  either  by  diffused  daylight  or  gas-  or  lamplight.  The  copy 
will  be  an  exact  reproduction  of  the  original,  showing  the  letters  or  figures  non-reversed. 
If  it  is  desired  to  make  a  copy  in  the  daytime,  any  dark  closet  will  answer,  where  all 
white  light  is  excluded.  The  tools  required  are  an  ordinary  photograph  printin"-  frame 
and  a  red  lantern  or  lamp.  The  sensitive  gelatine  paper  is  cut  to  the  size  required,  laid 
■with  the  sensitive  side  upward  upon  tlie  face  of  the  drawing,  and  pressed  thereon  in  the 
usual  maimer,  by  springs  at  the  back  of  the  frame,  which  is  then  carried  to  the 
window  and  exposed  with  the  glass  side  outward  for  2  to  5  seconds  to  the  light,  the 
exposure  varying  according  to  tiie  thickness  of  tlie  drawing.  If  gas-  or  lamplight  is 
used  at  night,  20  to  30  minutes'  exposure  is  sufficient.  The  frame  is  returned  to  the 
•dark  closet,  the  exposed  sheet  is  removed  to  a  dark  box,  and  other  duplicates  of  the 
drawing  can  be  made  in  the  same  way.  It  is  thus  possible  to  make  10  to  20  copies  of 
one  thick  drawing  in  the  same  time  that  it  usually  takes  to  obtain  one  copy  of  a  trans- 
parent tracing  by  the  ordinary  blue  process.  The  treatment  of  the  exposed  sheets  is 
quite  simple  ;  all  that  is  necessary  is  to  provide  3  or  4  large  pans  or  a  large  sink  divided 
into  partitions.  The  development  of  the  exposed  sheets  can  be  carried  on  at  night  or  at 
any  convenient  time,  but  a  red  light  only  must  be  used.  The  paper  is  first  passed 
through  a  dish  or  pan  of  water,  and  then  immersed  in  a  solution,  face  upwards,  composed 
of  8  parts  of  a  saturated  solution  of  potash  oxalate  to  1  of  a  saturated  solution  of  iron 
sulphate,  enough  to  cover  the  fiice  of  the  paper.  The  latent  image  soon  appears,  and  a 
beautiful  copy  of  the  drawing  is  obtained,  black  where  the  original  was  white,  with  clear 
white  lines  to  represent  the  black  lines  of  the  drawing.  With  one  solution,  6  to  8  copies 
can  be  developed  right  after  the  other.  After  development,  the  jirint  is  dipped  in  a  dish 
of  clear  water  for  a  minute,  and  finally  immersed  for  3  minutes  in  the  fixing  solution, 
composed  of  1  part  of  soda  hyposulphite  dissolved  in  C  of  water.  It  is  then  removed  to  a 
last  dish  of  water  face  downward,  soaked  for  a  few  minutes,  and  hung  up  to  dry  ;  when 
<lry  it  is  ready  for  use. 

Some  very  useful  suggestions  will  be  found  in  a  little  volume  by  Tuxford  Ilallatt, 
entitled  '  Hints  on  Architectural  Draughtsmanship.' 

CASTING  AND  FOUNDING.— The  following  remarks  by  W.  H.  Cooper  in 
ihe  School  of  Mines  Quarterly,  New  York,  give  a  very  clear  outline  of  the  operations  of 
casting  and  founding : — 

We  are  indebted  to  the  fusibility  of  the  metals  for  the  power  of  giving  to  them,  with 
great  facility  and  perfection,  any  required  form,  by  pouring  them,  whilst  in  a  fluid  state, 
into  moulds  of  various  kinds,  of  which,  in  general,  the  castings  become  exact  counter- 
parts. Some  few  objects  are  cast  ia  open  moulds,  the  upper  surface  of  the  metal 
becoming  flat  under  the  influence  of  gravity,  as  in  the  casting  of  ingots,  flat  plates,  and 
other  similar  objects  ;  but  in  general,  the  metals  are  cast  in  close  moulds,  so  that  it 
becomes  necessary  to  provide  one  or  more  apertures  or  ingates  for  pouring  in  the  metal, 
and  for  allowing  the  escape  of  air.  Moulds  made  of  metal  must  be  sufficiently  hot  to 
avoid  chilling  or  solidifying  the  fluid  metal  before  it  has  time  to  adapt  itself  throughout 
to  every  part  of  the  mould.  And  when  made  of  earthy  materials,  although  moisture  is 
essential  to  their  construction,  little  or  none  should  remain  at  the  time  they  are  filled. 
Earthen  moulds  must  also  be  so  pervious  to  air  that  any  vapour  or  gases  formed  either 
at  the  moment  of  casting  or  during  the  solidification  of  the  metal  may  easily  escape. 
Otherwise,  if  the  gases  are  rapidly  formed,  there  is  danger  that  the  metal  will  be  blown 
from  the  mould  with  a  violent  explosion,  or,  when  more  slowly  formed  and  unable  to 
escape,  the  bubbles  of  gas  will  displace  the  fluid  metal  and  render  it  spongy  or  porous. 


14  Casting  and  Founding. 

The  castinj?  is  then  said  to  he  "  hlown."  It  not  infrequently  occurs  that  castings  which 
appear  good  and  sound  externally  are  filled  with  hidden  defects,  hecause,  the  surface 
being  first  cooled,  the  bubbles  of  air  will  attempt  to  break  their  way  through  the  central 
and  still  soft  jiaris  of  the  metal. 

The  perfection  of  castings  depends  much  on  the  skill  of  the  pattern-maker,  who 
should  thoroughly  understand  the  practice  of  the  moulder,  or  he  is  liable  to  make  the 
patterns  in  such  a  manner  as  to  render  them  useless.  Straight-grained  deal,  pine,  and 
mahogany  are  the  best  woods  for  making  patterns,  as  they  remain  serviceable  longest. 
Screws  should  be  used  in  preference  to  nails,  as  alterations  may  be  more  easily  made, 
and  for  the  same  reason  dovetails,  tenons,  and  dowels  are  also  good.  Foundry  patterns 
should  always  be  made  a  little  tapering  in  tlie  parts  which  enter  most  deeply  into  the 
sand,  whenever  it  will  not  materially  injure  the  castings,  in  order  that  they  may  be 
more  easily  removed  after  moulding.  This  taper  amounts  to  Jg-  or  i  in.  per  ft.,  and 
sometimes  much  more.  When  foundry  patterns  are  exactly  parallel,  the  friction  of  the 
sand  against  their  sides  is  so  great  that  considerable  force  is  required  to  remove  them, 
and  the  sand  is  torn  down  unless  the  patterns  are  knocked  about  a  good  deal  in  the 
mould  to  enlarge  the  space  around  them.  This  rough  usage  frequently  injures  the 
patterns,  and  causes  the  castings  to  become  irregularly  larger  than  intended,  and 
defective  in  sliape,  from  the  mischief  sustained  by  the  moulds  and  patterns.  ' 

Sharp  internal  angles  should  be  avoided  as  much  as  possible,  as  they  leave  sharp 
edges  or  arrises  in  the  sand,  which  are  liable  to  be  broken  down  on  the  removal  of  the 
pattern,  or  washed  down  by  the  entry  of  the  metal  into  the  mould.  Either  the  angle  of 
the  mould  should  be  filled  with  wood,  wax,  or  putty,  or  the  sharp  edges  of  the  sand 
should  be  chamfered  off  with  a  knife  or  trowel.  Sharp  internal  angles  are  also  very 
injudicious  in  respect  to  the  strength  of  castings,  as  they  seem  to  denote  where  they 
will  be  likely  to  break.  Before  the  patterns  reach  the  founder's  hands,  all  the  glue 
remaining  on  their  surfaces  should  be  carefully  scraped  off,  or  it  will  adhere  to  and  break 
down  the  sand.  The  best  way  is  to  paint  or  varnish  wooden  patterns,  to  prevent  their 
absorbing  moisture  and  the  warping  of  the  surface  and  sticking  of  the  sand.  Whether 
painted  or  not,  they  deliver  better  from  the  mould  when  they  are  well  brushed  with 
blacklead. 

Foundry  patterns  are  also  made  in  metal.  These  are  excellent,  as  they  are  per- 
manent, and  when  very  small  are  less  liable  to  be  blown  away  by  the  bellows  used  for 
removing  the  loose  sand  and  dust  from  the  moulds.  To  prevent  iron  patterns  from 
rusting  and  to  make  them  deliver  more  easily,  they  should  be  allowed  to  become 
slightly  rusty,  and  then  warmed  and  beeswax  rubbed  over  them,  tlie  excess  removed, 
and  the  remainder  polished  after  cooling,  with  a  hard  brush.  Wax  is  also  used  by  the 
founder  for  stopping  up  any  little  holes  in  the  wooden  patterns.  Whiting  is  also  used 
for  this  purpose,  but  is  not  as  good.  Very  rough  patterns  are  seared  with  a  hot  iron. 
The  good  workman,  however,  leaves  no  necessity  for  these  corrections,  and  the  perfection 
of  the  pattern  is  well  repaid  by  the  superior  character  of  the  castings.  Metallic  patterns 
frequently  have  holes  tapped  in  them  for  receiving  handles,  which  screw  in,  to  facilitate 
their  removal  from  the  sand.  Large  wooden  patterns  should  also  have  iron  plates  let 
into  them,  into  which  handles  can  be  screwed.  Otherwise,  the  founder  is  obhged  to 
drive  pointed  wires  into  them,  and  thereby  injure  tlie  patterns. 

The  tools  used  in  making  the  moulds  are  few  and  simple— a  sieve,  shovel,  rammer, 
strike,  mallet,  a  knife,  and  2  or  3  loosening  wires  and  little  trowels,  which  it  is 
Tinnecessary  to  describe. 

The  principal  materials  for  making  foundry  moulds  are  very  fine  sand  and  loam. 
They  are  found  mixed  in  various  proportions,  so  that  the  proportion  proper  for  different 
uses  cannot  be  well  defined  ;  but  it  is  always  best  to  employ  the  least  quantity  of  loam 
that  will  suffice.  These  materials  are  seldom  used  in  the  raw  state  for  brass  casting, 
although  more  so  for  iron,  and  the  moulds  made  from  fresh  sand  arc  always  dried.    The 


Casting  and  Founding.  15 

ordinary  moulds  are  made  of  tho  old  damp  sand,  and  they  are  generally  poured  imme- 
diately, or  -while  they  are  green.  Sometimes  they  are  more  or  less  dried  upon  tho  face. 
The  old  working  sand  is  considerably  less  adhesive  than  the  new,  and  of  a  dark-brown 
colour.  This  arises  from  the  brick-dust,  flour,  and  charcoal-dust  used  in  tho  moulding 
becoming  mixed  with  the  general  stock.  Additions  of  fresh  sand  must  therefore  be 
occasionally  made,  so  that  when  slightly  moist  and  pressed  firmly  in  the  hand  it  may 
form  a  moderately  hard,  compact  lump. 

Red  brick-dust  is  generally  used  to  make  the  parting  of  the  mould,  or  to  jDrevent  the 
damp  sand  iu  the  separate  parts  of  the  flask  from  adhering  together.  The  face  of  tho 
mould  which  receives  the  metal  is  generally  dusted  with  meal,  or  waste  flour.  But  iu 
large  works,  powdered  chalk,  or  wood-  or  tan-ashes  are  used,  because  cheaper.  The 
moulds  for  the  finest  brass  castings  are  faced  either  with  charcoal,  loamstone,  rotten- 
stone,  or  mixtures  of  them.  The  moulds  are  frequently  inverted  and  dried  over  a  dull 
fire  of  cork  shavings,  or  when  dried  are  smoked  over  pitch  or  black  rosin  in  an  iron  ladle. 

The  cores  or  loose  internal  parts  of  the  moulds,  for  forming  holes  and  recesses,  are 
made  of  various  proportions  of  new  sand,  loam,  and  horse-dung.  They  all  require  to  be 
thoroughly  dried,  and  those  containing  horse-dung  must  be  well  burned  at  a  red  heat. 
This  consumes  the  straw,  and  makes  them  porous  and  of  a  brick-red  colour. 

In  making  the  various  moulds,  it  becomes  necessary  to  pursue  a  medium  course 
between  the  conditions  best  suited  to  the  formation  of  the  moulds  and  those  most 
suitable  for  the  filling  of  them  with  the  molten  metal  without  danger  of  accident. 
Thus,  within  certain  limits,  the  more  loam  and  moisture  the  sand  contains,  and  the 
more  closely  it  is  rammed,  the  better  will  be  the  impression  of  the  model ;  but  the  moist 
and  impervious  condition  of  the  mould  incurs  greater  risk  of  accident  both  from  the 
moisture  present  and  the  non-escape- of  the  air.  The  mould  should,  therefore,  be  made 
of  sand  which  is  as  dry  as  practicable,  to  render  the  mould  as  porous  as  possible. 
Where  much  loam  it  used,  the  moulds  must  be  thoroughly  dried  by  heat  before  casting 
the  metal. 

As  castings  contract  considerably  in  cooling,  the  moulds  for  large  and  slight  castings 
must  not  be  too  strongly  rammed  or  too  thoroughly  dried,  or  their  strength  may  exceed 
that  of  the  red-hot  metal  whilst  in  the  act  of  shrinking,  and  the  casting  be  broken  in 
consequence.  If  the  mould  is  the  weaker  of  the  two,  its  sides  will  simply  be  broken 
down  without  injury  to  the  casting. 

The  method  of  preparing  a  mould  is  as  follows :  The  sand  having  been  prepared, 
the  moulder  frees  the  patterns  from  all  glue  and  adhering  foreign  particles.  He  then 
selects  the  most  appropriate  "  flasks,"  which  are  frames,  or  boxes  without  top  or  bottom, 
made  of  wood,  for  containing  and  holding  the  sand.  The  models  are  then  examined  to 
ascertain  the  most  appropriate  way  of  inserting  them  into  the  sand.  The  bottom  flask  is 
then  placed  upon  a  board,  face  downwards.  A  small  portion  of  strong  facing-sand  is 
rubbed  through  a  sieve,  the  remainder  shovelled  in  and  driven  moderately  hard  into 
the  flask.  The  surface  is  then  struck  off  level  with  a  straight  metal  bar  or  scraper,  a 
little  loose  sand  sprinkled  on  tho  surface,  upon  which  another  board  is  placed  and 
rubbed  down  close.  The  2  boards  and  the  flask  between  them  are  then  turned  over 
together ;  the  top  board  is  removed,  and  fine  brick-dust  is  dusted  over  the  clean  surface 
of  moist  sand  from  a  linen  bag.  The  excess  of  brick-dust  is  removed  with  a  pair  of 
hand-bellows,  and  the  bottom  half  of  the  mould  is  then  ready  for  receiving  the  patterns. 
The  models  are  next  arranged  upon  the  face  of  the  sand,  so  as  to  leave  space  enough 
between  them  to  prevent  the  parts  breaking  into  each  other,  and  for  the  passages  by 
which  the  metal  is  to  be  introduced  and  the  air  allowed  to  escape.  Those  patterns 
which  are  cylindrical,  or  thick,  are  partly  sunk  into  the  sand  by  scraping  out  hollow 
recesses,  and  driving  the  models  in  with  a  mallet,  and  the  general  surface  of  the  sand 
repaired  with  a  knife,  trowel,  or  piece  of  sheet-steel.  The  level  of  the  sand  should 
coincide  with  that  of  the  greatest  diameter  or  section  of  the  model. 


IQ  Casting  and  Founding — Brass  and  Bronze. 

After  the  sand  is  made  good  to  the  edges  of  the  patterns,  brick -dust  is  again  shaken 
over  it,  the  patterns  also  receiving  a  portion.  The  upper  part  of  the  fJask  is  then  fitted 
to  the  lower  by  pins  of  iron  fitting  in  metal  eyes ;  and  a  little  strong  sand  is  sifted  in. 
It  is  then  filled  up  with  the  ordinary  sand,  which  is  rammed  down  and  struck  off  flush 
with  the  edge  of  the  flask.  The  dry  powder  serves  to  keep  the  2  halves  from  sticking 
together. 

In  order  to  open  the  mould  for  the  extraction  of  the  patterns,  a  board  is  placed  on 
the  top  of  the  flask  and  struck  smartly  at  different  places  with  a  mallet.  The  upper 
part  of  the  flask  is  then  gently  lifted  perpendicularly  and  inverted  on  its  board.  Should 
it  happen  that  any  considerable  portion  of  the  mould  is  broken  down  in  one  piece,  the 
•cavity  is  moistened  and  the  mould  is  again  carefully  closed  and  lightly  struck.  On  the 
second  lifting,  the  defect  will  usually  be  remedied.  All  breaks  in  the  sand  are  carefully 
repaired  before  the  extraction  of  the  patterns. 

To  remove  the  models,  they  are  driven  slightly  sidewise  with  taps  of  a  mallet,  so  as 
to  loosen  them  by  enlarging  the  space  around  them.  The  patterns  are  then  lifted  out, 
and  any  sand  which  may  have  been  torn  down  must  be  carefully  replaced,  or  fresh  sand 
is  used  for  the  repairing.  Should  the  flask  only  contain  one  or  two  objects,  the  ingate 
or  runner  is  now  scooped  out  of  the  sand,  so  as  to  lead  from  the  pouring-hole  to  the 
object.  Where  several  objects  arc  in  the  same  flask,  a  large  central  channel,  with 
branches,  is  made.  The  entrance  of  the  pouring-hole  is  smoothed  and  compressed,  and 
all  the  loose  sand  blown  out  of  the  mould  with  hand-bellows. 

The  faces  of  botli  halves  of  the  mould  are  next  dusted  with  meal-dust  or  waste  flour, 
put  together,  and  the  boards  replaced — one  just  flush  with  the  side  of  the  flask  in  which 
the  pouring-hole  is  situated,  and  the  other  (on  the  side  from  which  the  metal  is  to  be 
poured)  is  put  about  2  in.  below,  and  secured  by  hand-screws.  The  mould  is  then  held 
mouth  downwards,  that  any  sand  loosened  in  the  screwing  down  may  fall  out.  It  is  now 
ready  to  be  filled. 

Where  the  bottom  half  of  the  flask  requires  to  be  much  cut  away  for  imbedding  the 
patterns,  it  is  usual,  when  the  second  half  is  completed,  to  destroy  the  first  or  "  false  " 
side,  which  has-been  hastily  made,  and  to  repeat  it  by  inverting  the  upper  flask  and 
proceeding  as  before. 

When  many  copies  of  the  same  patterns  are  required,  an  "  odd  side  "  is  prepared — 
that  is,  a  flask  is  chosen  which  has  one  upper  and  two  lower  portions.  One  of  the  latter 
is  carefully  arranged,  with  all  the  patterns  barely  half-way  imbedded  in  the  sand,  so  that 
when  the  top  is  filled,  and  both  are  turned  over,  all  of  the  patterns  are  left  in  the  new 
side.  A  second  lower  portion  is  then  made  for  receiving  the  metal  while  the  first  one  is 
kept  for  rearranging  the  patterns.  By  this  plan,  the  trouble  of  arranging  the  patterns 
for  every  separate  mould  is  avoided,  as  the  patterns  are  simply  replaced  in  the  odd  side 
and  the  routine  of  forming  the  two  working-sides  is  repeated.     (W.  II.  Cooper.) 

Brass  and  Bronze  Founding. — A  vast  number  of  articles,  chiefly  small  in  size 
and  of  a  more  or  less  artistic  character,  are  cast  in  brass,  bronze,  or  one  of  the  many 
modifications  of  these  well-known  alloys. 

Pure  copper  is  moulded  with  dilliculty,  because  it  is  often  filled  with  flaws  and  air- 
bubbles,  which  spoil  the  casting;  but  by  alloying  it  with  a  certain  quantity  of  zinc,  a 
metal  is  obtained  free  from  this  objection,  harder  and  more  easily  worked  in  the  lathe. 
Zinc  renders  tlie  colour  of  copper  more  pale  ;  and  when  it  exists  in  certain  proportions  in 
the  alloy,  it  conuuunicates  to  it  a  yellow  hue,  resembling  that  of  gold  ;  but  when  present 
in  large  quantity  the  colour  is  a  bright  yellow  ;  and,  lastly,  when  the  zinc  predominates, 
the  alloy  becomes  of  a  greyish  white.  Various  names  are  given  to  these  different  alloys. 
The  one  most  used  in  the  arts  is  brass,  or  yellow  copper,  composed  of  about  |  of  copper 
and  i  of  zinc.  Other  alloys  are  also  known  in  commerce,  by  the  names  of  tombac,  similor 
or  l^Iannheim  gohl,  pinchbeck  or  prince's  metal  (chrysocale),  &c. ;  they  contain  in 
addition  greater  or  less  quantities  of  tin.    Tombac,  used  for  ornamental  objects  which 


Casting  and  Founding — Brass  and  Bronze.  17 

are  iutended  to  be  gilded,  contnins  10-14  per  cent,  of  zinc ;  the  composition  of  Dutch 
gold,  which  Ciin  be  hammeied  into  very  thin  sheets,  being  nearly  the  same.  Siniilor,  or 
Mannheim  gold,  contains  10-12  per  cent,  of  zinc  and  6-8  of  tin ;  and  pinchbeck  con- 
tains G-8  per  cent,  of  zinc  and  G  of  tin.  If  brass  be  heated  in  a  brasqued  crucible  in  a 
forge-fire,  the  zinc  is  nearly  wholly  driven  off.  Brass  is  made  by  melting  directly  copper 
and  zinc  ;  rosette  copper  being  used,  fused  in  a  crucible,  and  run  into  water  to  granulate 
it.  The  zinc  is  broken  into  small  pieces.  The  fusion  is  effected  in  earthen  crucibles 
which  can  contain  SO-IO  lb.  of  alloy,  the  metals  being  introduced  in  the  proportion  of 
I  of  copper  and  i  of  zinc,  to  which  scraps  of  brass  are  added.  .Small  quantities  of  lead 
and  tin  are  frequently  added  to  brass  to  make  the  alloy  harder  and  more  easily  worked  ; 
brass  which  contains  no  lead  soon  chokes  a  file,  which  defect  is  remedied  by  the  addition 
of  1  or  2  hundredths  of  lead. 

Copper  and  tin  mix  in  various  proportions,  and  form  alloys  which  differ  vastly  in 
appearance  and  physical  properties,  as  tin  imparts  a  great  degree  of  hardness  to  copper. 
Before  the  ancients  became  acquainted  with  iron  and  steel,  they  made  their  arms  and 
cutting  instruments  of  bronze,  composed  of  copper  and  tin.  Copper  and  tin,  however, 
combine  with  difficulty,  and  their  union  is  never  very  perfect.  By  heating  their  alloys 
gradually  and  slowly  to  the  fusing  point,  a  large  portion  of  the  tin  will  separate  by 
eliquation,  which  effect  also  occurs  when  the  melted  alloys  solidify  slowly,  causing 
circumstances  of  serious  embarrassment  in  casting  large  pieces.  Different  names  are 
given  to  the  alloys  of  copper  and  tin,  according  to  their  composition  and  uses:  they  are 
called  bronze  or  brass,  cannon-metal,  bell-metal,  telescope-speculum  metal,  &c.  All  these 
alloys  have  one  remarkable  property:  they  become  hard  and  frequently  brittle,  when 
slowly  cooled,  while  they  are,  on  the  contrary,  malleable  when  they  are  plunged  into 
cold  water,  after  having  been  heated  to  redness.  Tempering  produces,  therefore,  in  these 
alloys  an  effect  precisely  opposite  to  that  produced  on  steel.  When  alloys  of  copper  and 
tin  are  melted  in  the  air,  the  tin  oxidizes  more  rapidly  than  the  copper,  and  pure  copper 
may  be  separated  by  continuing  the  roasting  for  a  sufficient  length  of  time. 

Furnaces. — Furnaces  for  melting  brass  or  bronze  may  be  built  of  common  brick  and 
lined  with  fire-brick ;  but  the  best  are  made  with  a  boiler-plate  caisson,  20-30  in.  diam. 
and  30-40  in.  high,  usually  set  down  in  a  pit,  with  the  top  only  10  or  12  in.  above  the 
floor  of  the  foundry.  The  ash-pit,  or  opening  around  the  furnace,  is  covered  by  a  loose 
wooden  grating,  that  admits  of  the  ashes  being  removed.  The  iron  caisson  is  lined  with 
fire-brick,  the  same  as  a  cupola,  the  lining  being  usually  6  in.  or  more  thick.  The  inside 
diameter  of  the  furnace  should  not  exceed  the  outside  diameter  of  the  crucible  by  more 
than  4  or  5  in.,  as  greater  space  will  require  greater  expenditure  of  fuel.  These  furnaces 
are  liable  to  burn  hollow  around  where  the  crucible  rests  ;  to  avoid  waste  of  fuel,  they 
should  be  kept  straiglitened  up  with  fire-clay  and  sand.  Sometimes  these  furnaces  are 
built  square  inside,  but  they  are  inferior  to  the  circular  form  and  consume  more  fuel ;  3  or 
4  such  furnaces  are  commonly  arranged  in  sets  giving  a  graduated  scale  of  sizes,  to  «uit 
the  needs  of  large  or  smaller  castings.  When  the  quantity  of  metal  used  is  large,  a  blast 
is  generally  employed.  The  common  brass  furnace  usually  depends  on  a  natural  drau 
and  connects  by  a  flue  with  a  chimney  stack  at  the  back ;  3  or  4  commonly  share  a 
single  stack,  each  having  a  separate  flue  and  damper.  When  the  chimney  does  not  give 
sufficient  draught,  the  ash-pit  may  be  tightly  closed,  and  a  mild  blast  turned  into  the  pit, 
to  find  its  way  up  through  the  grates.  The  fuel  may  be  hard  coal  or  coke,  broken  inta 
lumps  about  the  size  of  hens'  eggs ;  coke  is  preferable  as  heating  more  rapidly,  and  thus 
lessening  the  oxidation  of  metal,  but  gas-coke  from  cannel  coal  is  not  admissible. 

The  ordinary  cupola  furnace  is  shown  in  Fig.  1.  It  consists  of  a  circular  chamber 
a  built  of  fire-brick,  rising  in  the  form  of  a  dome,  in  the  top  of  which  is  a  circular 
opening,  carrying  a  cast-iron  ring  6,  through  which  the  pots  and  fuel  are  introduced.  At 
the  bottom  is  a  bed-plate  c,  which  is  a  circular  plate  of  cast-iron  having  one  large  hole 
d  in  the  centre  (for  the  withdrawal  of  ashes  and  clinkers),  and  12  emalleronee  e  arrangetl 

c 


+ 


18 


Casting  and  Founding — Brass  and  Bronze. 


symmetrically  ftroiind  it.  Below  the  bed -pi ate  is  the  ash-pit  /  leading  to  an  arched 
air  passage  g,  which  supplies  air  to  the  ash-pit.  Tapering  cast-iron  nozzles,  6  in.  high, 
3  in.  diameter  at  the  bottom,  1 J  in.  at  the  top,  and  about  J  in.  thick,  are  placed  over  the 
12  email  holes  e.  The  space  between  the  top  of  the  bed-plate  and  the  top  of  the 
nozzles  is  built  up  with  fire-brick  and  fire-clay  until  it  forms  a  surface  perfectly  level 
with  the  top  of  Ihe  small  nozzles,  leaving  the  central  hole  free.  These  nozzles  do  the  duty 


1. 


1 


of  a  fire-grate,  by  admitting  the  air  that  supports  combustion.  The  whole  construction 
is  enclosed  in  a  solid  mass  of  brickwork,  and  an  iron  bar  h  is  built  in  over  the  air-way 
in  front  of  the  bed-plate,  and  resting  on  the  walls  forming  the  sides  of  the  air-way,  to 
give  support.  The  dimensions  of  the  furnace  shown  are  3  ft.  6  in.  diameter,  and 
3  ft.  6  in.  height  from  furnace  bed  to  crown  of  arch. 

The  ordinary  molting  furnace  is  shown  in  Fig.  2.  The  fire-place  a  is  lined  throughout 
with  fire-brick,  as  well  as  the  opening  d  into  the  flue  and  a  portion  of  the  flue  e  itself; 
h  is  the  ash-pit;  c,  register-door  of  ash-pit,  by  which  the  draught  is  partially  regulated; 
/,  fire-brick  cover  for  the  furnace ;  g,  fire-bars.  It  is  built  all  round  with  common  brick  ; 
and  as  many  as  G  may  use  Ihe  same  stack. 

Fig.  3  illustrates  tlie  circular  melting  furnace,  consisting  of  an  iron  plate  a  pierced, 
in  the  centre  by  a  circular  hole  of  the  size  of  the  interior  of  the  furnace,  and  crossed  by. 


Casting  and  Founding — Brass  and  Bronze. 


19 


tlie  fire-bnrs  ;  ?>  is  a  sheet-iron  drum  riveted  together,  forming  the  shell  of  the  furnace, 
and  resting  on  the  bed-plate  ;  it  is  first  Ihied  on  the  inside  with  4i  in.  of  ordinary  brick, 
and  next  with  9  in.  of  fire-brick ;  c,  fire-place  ;  d,  flue  leading  to  stack ;  e,  iron  grating 


for  admitting  air  beneath  the  furnace;/,  ash-pit;  g,  4  small  brickwork  pillars,  about 
IS  in.  high,  supporting  the  bed-plate ;  h,  fire-brick  cover  to   furnace.     The  draught  is 
regulated  by  a  damper  in  the  line  or  on  the  stack.     The  latter  is  an  iron  plate  large 
enough  to  entirely  cover  the  top  of  the  stack, 
hinged  at  one  edge,  and  open  or   closed  by  a 
lever. 

A  rcverberatory  furnace  is  illustrated  in 
Pig.  -1 :  a,  fire-place ;  b,  ash-pit ;  c,  bridge  ;  d, 
melting  furnace ;  e,  fire-door ;  /,  flue  leading  to 
stack;  g,  door  for  feeding  in  and  ladling  out 
metal.  The  draught  is  regulated  by  the  fire- 
door  and  the  damper  on  the  top  of  the  stack. 

Crucibles. — All  the  metals  and  alloys,  with 
the  exception  of  iron  and  the  very  fusible  metals, 
are  melted  in  crucibles,  of  which  there  are 
several  diiferent  kinds.  The  jirincipal  ones  in  use 
are  the  Hessian  pots,  the  English  brown  or  clay 
pots,  the  Cornish  and  the  Wedgwood  crucibles — 
all  extensively  used  for  melting  alloys  of  brass, 
hell-metal,  gun-metal,  &c. ;  but  they  are  very 
brittle,  and  seldom  stand  more  than  one  heat,  yet 
are  generally  sold  cheap,  and  some  founders 
prefer  to  use  a  crucible  only  once,  for  crucibles 
often  crack  or  burn  through  on  the  second  heat. 
The  best  crucibles  for  all  kinds  of  alloys  are  made  of  graphite  (miscalled  plumbago 
and  blacldead).  These  are  sold  higher  than  any  of  the  clay  crucibles,  but  they  are 
more  refractory,  and  may  be  used  for  3  or  more  successive  heata  without  any  danger 

o2 


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•'■["' ■•■"■r-"v'7r;:T"  r'  r:  t^j~ 


20  Casting  and  Founding — Brass  and  Bronze. 

of  cracking  or  burning  through.  They  are  not  so  oi3cn  and  porous  as  the  clay 
crucibles,  ami  do  not  absorb  so  much  of  the  metal,  and  for  tliis  reason  they  are 
to  be  preferred  for  melting  valuable  metals.  "When  about  to  use  a  crucible,  it  should 
be  heated  gradually  by  putting  it  in  the  furnace  when  the  iiro  is  started,  or  by 
settiag  it  on  the  top  of  the  tyle  or  covering  of  the  furnace,  with  the  moutli  down  ; 
it  should  be  heated  in  this  way  until  it  is  almost  too  hot  to  hold  in  the  hands. 
Some  founders  stand  a  fire-brick  on  end  in  the  bottom  of  the  furnace  to  set  the  crucible- 
on.  This  prevents  the  crucible  from  settling  with  the  fuel  as  it  is  burnt  away.  This 
way  of  supporting  the  crucible  is  a  good  idea  when  tho  furnace  has  a  poor  draught 
and  the  metal  is  melted  slowly  and  it  is  necessary  to  replenish  tho  fuel  before  the  metal 
can  be  melted;  but  in  furnaces  -where  the  metal  is  melted  quickly,  and  it  is  not 
necessary  to  replenish  the  fuel  in  the  middle  of  the  heat,  the  crucible  should  be 
allowed  to  settle  with  the  fuel,  as  the  heat  will  then  bo  more  concentrated  upon 
it.  After  the  metal  has  been  poured  from  the  crucible  into  the  mould  or  ingot^ 
the  crucible  should  always  be  returned  to  the  furnace,  and  allowed  to  cool  off  with  tho 
furnace  to  prevent  it  from  cracking.  In  forming  alloys  of  brass,  &c.,  a  lid  for  the 
crucible  is  seldom  used,  but  a  covering  of  charcoal  or  some  kind  ot  flux  is  generally  laid 
on  the  metal.  The  metal  to  be  melted  in  the  crucible  is  generally  packed  in  before 
the  crucible  is  put  into  the  furnace ;  and  when  it  is  desirable  to  add  to  the  metal  after 
some  has  been  fused,  it  is  put  in  with  the  tongs,  if  in  large  pieces  ;  but  when  the  metal 
to  be  added  is  in  small  pieces,  it  is  put  into  the  crucible  through  a  long  funnel-shaped, 
pipe.  The  small  end  of  this  pipe  is  used  for  putting  metals  into  the  crucible,  <and  the 
large  end  is  used  for  covering  the  crucible  to  prevent  the  small  pieces  of  fuel  from 
falling  in. 

Moulding. — Brass  moulding  is  carried  on  by  means  of  earthen  or  sand  moulds. 
The  formation  of  sand  moulds  is  by  no  means  so  simple  an  affair  as  it  would  first  appear, 
for  it  requires  long  practical  experience  to  overcome  tho  disadvantages  attendant  upon 
the  material  used.  The  moulds  must  be  sufficiently  strong  to  withstand  the  action  of 
the  fluid  metal  perfectly,  and,  at  the  same  time,  must  bo  so  far  pervious  to  the  air  as  to 
permit  of  the  egress  of  the  gases  formed  by  the  action  of  the  metal  on  the  sand.  If 
the  material  were  perfectly  air-light,  then  damage  would  ensue  from  the  pressure  arising 
out  of  the  rapid  generation  of  gases,  which  would  spoil  the  effect  of  the  casting,  and 
probably  do  serious  injury  to  the  operator.  If  the  gases  are  locked  up  within  the  mould, 
the  general  result  is  what  moulders  term  a  "blown  "  casting;  that  is,  its  surface  becomes 
filled  with  bubbles,  rendering  its  texture  porous  and  weak,  besides  injuring  its  appearance. 

For  a  number  of  the  more  fusible  metals,  plaster  of  Paris  is  used.  This  material, 
however,  will  not  answer  for  the  more  refractory  ones,  as  the  heat  causes  it  to  crumble 
away  and  lose  its  shape.  Sand,  mixed  with  clay  or  loam,  possesses  advantages  not  to  be 
found  in  gypsum,  and  is  consequently  used  in  place  of  it  for  brass  and  other  alloys. 
In  the  formation  of  brass  moulds,  old  damp  sand  is  principally  used  in  preference  to  tho 
fresh  material,  being  much  less  adhesive,  and  allowing  the  patterns  to  leave  the  moulds, 
easier  and  cleaner.  Meal-dust  or  flour  is  used  for  facing  the  moulds  of  small  articles, 
but  for  larger  works,  powdered  chalk,  wood  ashes,  and  so  on  are  used,  as  being  more 
economical.  If  particularly  fine  work  is  required,  a  facing  of  charcoal  or  rottenstone  is 
applied.  Another  plan  for  giving  a  fiue  surface  is  to  dry  the  moulds  over  a  slow  fire 
of  cork  shavings,  or  other  carbonaceous  substance,  which  deposits  a  fine  thin  coating  of 
carbon.  This  is  done  when  good  fine  facing-sand  is  not  to  be  obtained.  As  regards  the 
proportions  of  sand  and  loam  used  in  the  formation  of  tho  moulds,  it  is  to  be  remarked 
that  the  greater  the  quantity  of  the  former  material,  the  more  easily  will  the  gases  escape, 
and  the  less  ILkelilKwd  is  there  of  a  failure  of  tho  casting  ;  on  tho  other  hand  if  the 
latter  substance  predominates,  the  impression  of  the  pattern  will  be  better,  but  a  far 
greater  liability  of  injury  to  the  casting  will  be  incurred  from  the  impermeable  nature  of 
the  moulding  material.     This,  however,  may  be  got  over  without  the  slighest  risk,  by 


I 


Casting  and  Founding — Brass  and  Bronze.  21 

•well  di-j-ingthe  mould  prior  to  casting,  as  would  have  to  be  done  were  the  mould  entirely 
of  Itiam. 

Where  easily  fusible  metal  is  used,  metallic  moulds  are  sometimes  adopted.  Thus, 
where  great  quantities  of  one  particular  species  of  casting  are  required,  the  metallic 
mould  is  cheaper,  easier  of  management,  and  possesses  the  advantage  of  producing  any 
number  of  exactly  similar  copies.  The  simplest  example  is  the  casting  of  bullets. 
These  are  cast  in  moulds  constructed  like  scissors,  or  pliers,  the  jaws  or  nipping  portions 
being  hollowed  out  homispherically,  so  that  when  closed  a  complete  hollow  sphere  is 
formed,  having  a  small  aperture  leading  into  the  centre  of  the  division  line,  by  which  the 
molten  lead  is  poured  in.  Pewter  pots,  inkstands,  printing  types,  and  various  other 
articles,  composed  of  the  easily  fusible  metals,  or  their  compounds,  are  moulded  on 
the  same  principle.  The  pewterer  generally  uses  brass  moulds  :  they  are  heated  previous 
to  pouring  in  the  metal.  In  order  to  cause  the  casting  to  leave  the  mould  easier,  as  well 
as  to  give  a  finer  face  to  the  article,  the  mould  is  brushed  thinly  over  with  red  ochre 
and  white  of  an  egg ;  in  some  cases  a  tliin  film  of  oil  is  used  instead.  Many  of  the 
moulds  for  this  purpose  are  extremely  complex,  and,  being  made  in  several  pieces,  they 
require  great  care  in  fitting. 

A  few  observations  on  the  method  of  filling  the  moulds.  The  experienced  find 
that  the  proper  time  for  pouring  the  metal  is  indicated  by  the  wasting  of  the  zinc,  which 
gives  olT  a  lambent  flame  from  the  surface  of  the  melted  metal.  The  moment  this  is 
observed,  the  crucible  is  removed  from  the  fire,  in  order  to  avoid  incurring  a  great  waste 
of  this  volatile  substance.  The  metal  is  then  immediately  poured.  The  best  tem- 
perature for  pouring  is  that  at  which  it  will  take  the  sharpest  impression  and  yet  cool 
quickly.  If  the  metal  is  very  hot,  and  remains  long  in  contact  with  the  mould,  what  is 
called  "sand-burning"  takes  place,  and  the  face  of  the  casting  is  injured.  The 
founder,  then,  must  rely  on  his  own  judgment  as  to  what  is  the  lowest  heat  at  which 
good,  sharp  impressions  will  be  produced.  As  a  rule,  the  smallest  and  thinnest  castings 
must  be  cast  the  first  in  a  pouring,  as  the  metal  cools  quickest  in  such  cases,  while  the 
reverse  holds  good  with  regard  to  larger  ones. 

Complex  objects,  when  inflammable,  aro  occasionally  moulded  in  brass,  and  some 
other  of  the  fusible  metals,  by  an  extremely  ingenious  process ;  rendering  what  other- 
wise would  be  a  difficult  problem  a  comparatively  easy  matter.  The  mould,  which  it 
must  be  understood  is  to  be  composed  of  some  inflammable  material,  is  to  be  placed  in 
the  sand-flask,  and  the  moulding  sand  is  put  in  gradually  until  the  box  is  filled  up. 
Tyheu  dry,  the  whole  is  placed  in  an  oven  sufliciently  hot  to  reduce  the  mould  to  ashes, 
which  are  easily  removed  from  their  hollow,  when  the  metal  may  be  poured  in.  In 
"this  way  small  animals,  birds,  or  vegetables  may  be  cast  with  the  greatest  facility.  The 
animal  is  to  be  placed  in  the  empty  moulding  box,  being  held  in  the  exact  position 
required  by  suitable  wires  or  strings,  which  may  be  burnt  or  removed  previous  to 
pouring  in  the  metal. 

Another  mode,  which  appears  to  be  founded  on  the  same  principle,  answers  perfectly 
"well  when  the  original  model  is  moulded  in  wax.  The  model  is  placed  in  the  moulding 
box  in  the  manner  detailed  in  the  last  process,  having  an  additional  piece  of  wax  to 
represent  the  runner  for  the  metal.  Tlie  composition  here  used  for  moulding  is  similar 
to  that  employed  by  statue  founders  in  forming  the  cores  for  statues,  busts,  and  so  on, 
namely,  2  parts  brickdust  to  1  of  plaster  of  Paris.  This  is  mixed  with  water,  and 
poured  in  so  as  to  surround  the  model  well.  The  whole  is  then  slowly  dried,  and  when 
the  mould  is  sufficiently  hardened  to  withstand  the  effects  of  the  molten  wax,  it  is 
warmed,  in  order  to  liquefy  and  pour  it  out.  When  clear  of  the  wax,  the  mould  is  dried 
and  bmried  in  sand,  in  order  to  sustain  it  against  the  action  of  the  fluid  metal. 

Large  bells  are  usually  cast  in  loam  moulds,  being  "swept"  up,  according  to  the 
founder's  phraseology,  by  means  of  wooden  or  metal  patterns  whose  contour  is  an  exact 
representation  of  the  inner  and  outer  surfaces  of  the  intended  bell.     Sometimes,  indeed, 


22  Casting  and  Founding — Brass  and  Bronze. 

the  ■wliole  exterior  of  the  bell  is  moulded  in  was,  which  serves  as  a  model  to  form  the 
impression  in  the  sand,  the  wax  being  melted  out  previous  to  peuring  in  the  metal. 
This  plan  is  rarely  pursued,  and  is  only  feasible  when  the  casting  is  small.  The  in- 
scriptions, ornaments,  scrolls,  and  so  on,  usually  found  on  bells,  are  put  on  tlie  clay  mould 
separately,  being  moulded  in  wax  or  clay,  and  stuck  on  while  soft.  The  same  i>\an  is 
pursued  with  regard  to  the  ears,  or  supporting  lugs,  by  which  the  bell  is  hung. 

Moulds  faced  with  common  flour  turn  out  castings  beautifully  smooth  and  bright; 
the  sand  parts  easily  from  the  surfaces,  and,  as  a  rule,  can  be  readily  removed  by  the 
application  of  a  hard  brush.  For  large  brass  castings,  quicklime  is  successfully  used  in 
some  places ;  it  is  simply  dusted  on  the  face  of  the  mould  and  smoothed  down  in  the 
usual  way. 

Sometimes,  even  when  the  brass  mixtures  are  good,  there  will  be  much  trouble 
with  blowing,  both  in  dry  and  green  moulds.  This  may  be  due  to  want  of  porosity  in 
the  sand  or  to  iusufSeient  heat  of  metal.  A  first-class  sand  is  that  from  the  Mansfield 
quarries,  near  Nottingham.  It  is  a  good  plan  to  stir  the  metal  with  a  hazel  rod  juit 
before  pouring. 

The  ordinary  method  of  casting  in  sand  moulds  applied  in  successive  pieces,  as  in 
plaster  of  Paris  casting,  is  not  so  much  in  use  in  Italy  as  what  is  called  the  "  forma 
perduta  "  mode  ;  meaning  that  the  object  is  destroyed  or  "  lost "  every  time.  Casting 
from  metallic  or  other  incombustible  objects  is  therefore  impossible  by  this  method. 
The  object  must  be  of  wax,  or  something  that  will  melt  or  burn  out,  the  mould 
having  been  dried  and  baked.  By  this  way  very  little  chasing  is  required,  but  the 
artist  has  to  finish  his  wax  object  (cast  in  a  plaster  mould)  each  time.  The  advantage 
of  this  method  is  that  you  get  the  artist's  finishing  of  his  own  work  instead  of  the 
chaser's,  who,  though  he  ought  to  be,  is  by  no  means  always  an  artist.  He  can  copy 
mechanically,  but  the  work  always  loses  terribly  in  expression  and  finish. 

The  following  process  is  recommended  by  Abbass  for  j)roducing  metallic  castings  of 
flowers,  leaves,  insects,  &c.  The  object — a  dead  beetle,  for  example — is  first  arranged 
in  a  natural  position,  and  the  feet  are  connected  with  an  oval  rim  of  wax.  It  is  then 
fixed  in  the  centre  of  a  paper  or  wooden  box  by  means  of  pieces  of  fine  wire,  so  that  it 
is  perfectly  free,  and  thicker  wires  are  run  from  the  sides  of  the  box  to  the  object, 
which  subsequently  serve  to  form  air-channels  in  the  mould  by  their  removal.  A  wooden 
stick,  tapering  towards  the  bottom,  is  placed  upon  the  back  of  the  insect  to  produce  a 
runner  for  casting.  The  box  is  then  filled  up  with  a  paste  of  |  plaster  of  Paris  and  | 
brickdust,  made  up  with  a  solution  of  alum  and  sal-ammoniac.  It  is  also  well  first  to 
brush  the  object  with  this  paste  to  prevent  the  formation  of  air-bubbles.  After  the 
mould  thus  formed  has  set,  the  object  is  removed  from  the  interior  by  first  reducing  it  to 
ashes.  It  is  therefore  dried  slowly,  and  finally  heated  gradually  to  a  red  heat,  and  then 
allowed  to  cool  slowly  to  prevent  the  formation  of  flaws  or  cracks.  The  ashes  are  removed 
by  pouring  mercury  into  the  cold  mould  and  shaking  it  thoroughly  before  pouring  it 
out,  repeating  this  operation  several  times.  The  thicker  wires  are  then  drawn  out, 
and  the  mould  needs  simply  to  be  thoroughly  heated  before  it  is  filled  with  metal, 
in  order  that  tlie  latter  may  flow  into  all  portions  of  it.  After  it  has  become  cold,  it  is 
softened  and  carefully  broken  away  from  the  casting. 

Casting. — When  brass  is  ready  to  be  poured,  the  zinc  on  the  surface  begins  to  waste 
with  a  lambent  flame.  When  this  condition  is  observed,  the  large  cokes  are  iii-st 
removed  from  the  mouth  of  the  pot,  and  a  long  pair  of  crucible  tongs  are  thrust  down 
beside  the  same  to  embrace  it  securely,  after  which  a  coupler  is  dropped  upon  the 
handles  of  tlie  tongs ;  the  pot  is  now  lifted  out  with  both  hands  and  carried  to  the 
skimming  place,  where  the  loose  dross  is  skimmed  off  with  an  iron  rod,  and  the  pot  is 
rested  upon  the  spill-trough,  against  or  upon  which  the  flasks  are  arranged. 

The  temperature  at  which  the  metal  is  poured  must  bo  proportioned  to  the 
magnitude  of  the  work ;  thus,  large,  struggling,  and  thin  castings  require  the  metal  to 


\ 


Casting  and  Founding — Brass  and  Bronze.  23 

be  very  hot,  otherwise  it  will  be  chilled  from  coming  in  contact  with  tho  extended 
surface  of  sand  before  having  entirely  filled  the  mould  ;  thick  massive  castings,  if  filled 
with  such  hot  metal,  would  be  sandburnt,  as  the  long  continuance  of  the  licat  would 
destroy  the  face  of  the  mould  before  the  metal  would  be  solidified.  The  lino  of  policy 
seems  therefore  to  be,  to  pour  the  metals  at  that  period  when  they  shall  bo  suiticiently 
fluid  to  fill  the  moulcls  perfectly,  and  produce  distinct  and  sharp  impressions,  but  that 
the  metal  shall  become  externally  congealed  as  soon  as  possible  afterwards. 

For  slight  moulds,  the  carbonaceous  facings,  whether  meal-dust,  charcoal,  or  soot, 
are  good,  as  these  substances  are  bad  conductors  of  heat,  and  rather  aid  than  otherwise 
by  their  ignition ;  it  is  also  proper  to  air  these  moulds  for  thin  works,  or  slightly  warm 
them  before  a  grate  containing  a  coke  fire.  But  in  massive  works  these  precautions 
are  less  required ;  and  the  facing  of  common  brickdust,  which  is  incombustible  and 
more  binding,  succeeds  better. 

The  founder  therefore  fills  the  moulds  having  the  slightest  works  first,  and 
gradually  proceeds  to  the  heaviest ;  if  needful,  he  will  wait  a  little  to  cool  the  metal,  or 
will  effect  the  same  purpose  by  stirring  it  with  one  of  the  ridges  or  waste  runners, 
which  thereby  becomes  partially  melted.  He  judges  of  the  temperature  of  tho  melted 
brass  principally  by  the  eye,  as,  when  out  of  the  furnace,  and  the  very  hot  surface  emits 
a  brilliant  bluish-white  flame,  and  gives  off  clouds  of  white  oxide  of  zinc,  a 
considerable  portion  of  which  floats  in  the  air  like  snow,  the  light  decreases  with  the 
temperature,  and  but  little  zinc  is  then  fumed  away. 

Gun-metal  and  pot-metal  do  not  flare  away  in  the  manner  of  brass,  the  tin  and  lead 
being  far  less  volatile  than  zinc ;  neither  should  they  be  poured  so  hot  or  fluid  as 
yellow  brass,  or  they  will  become  sandburnt  in  a  greater  degree,  or,  rather,  the  tin 
and  lead  will  strike  to  the  surface.  Gun-metal  and  the  much-used  alloys  of  copper, 
tin,  and  zinc  are  sometimes  mixed  at  the  time  of  pouring;  the  alloy  of  lead  and 
copper  is  never  so  treated,  but  always  contains  old  metal,  and  copper  is  seldom  cast 
alone,  but  a  trifling  portion  of  zinc  is  added  to  it,  otherwise  the  work  becomes  nearly 
full  of  little  air-bubbles  throughout  its  surface. 

AVhen  the  founder  is  in  doubt  as  to  the  quality  of  the  metal,  from  its  containing 
old  metal  of  unknown  character,  or  if  he  desires  to  be  very  exact,  he  will  either  pour 
a  sample  from  the  pot  into  an  ingot-mould,  or  extract  a  little  with  a  long  rod  terminating 
in  a  spoon  heated  to  redness.  The  lump  is  cooled,  and  tried  with  a  file,  saw,  hammer, 
or  drill,  to  learn  its  quality.  The  engraved  cylinders  for  calico-printing  arc  required 
to  be  of  pure  copper,  and  their  unsoundness,  when  cast  in  the  usual  way,  was  found  to 
be  £0  serious  an  evil  that  it  gave  rise  to  casting  the  metal  under  pressure. 

Some  jjersons  judge  of  the  heat  proper  for  pouring  by  applying  the  skimmer  to  the 
surface  of  the  metal,  which,  when  very  hot,'has  a  motion  like  that  of  boiling  water  ; 
this  dies  away  and  becomes  more  languid  as  the  metal  cools.  Many  works  are  spoiled 
from  being  poured  too  hot,  and  the  management  of  the  heat  is  much  more  difficult  when 
the  quantity  of  metal  is  small.  In  pouring  the  metal,  care  should  be  taken  to  keep 
back  the  dross  from  the  liiJ  of  the  melting-pot.  A  crucible  containing  the  general 
quantity  of  40  lb.  or  50  lb.  of  metal  can  be  very  conveniently  managed  by  one  individual, 
but  for  larger  quantities,  sometimes  amounting  to  1  cwt.,  an  assistant  aids  in  supporting 
the  crucible  by  catching  hold  of  the  shoulder  of  the  tongs  with  a  grunter,  an  irdn  rod 
bent  like  a  hook. 

Whilst  the  mould  is  being  filled,  there  is  a  rushing  or  hissing  sound  from  the  flow  of 
metal  and  escape  of  air ;  the  effect  is  less  violent  where  there  are  2  or  more  passages, 
as  in  heavy  pieces,  and  then  the  jet  can  be  kept  entirely  full,  which  is  desirable. 
Immediately  after  the  mould  is  filled,  there  are  generally  small  but  harmless  explosions 
of  the  gases,  which  escape  through  the  seams  of  the  mould ;  they  ignite  from  the 
runners,  and  burn  quietly ;  but  when  the  metal  blows,  from  tho  after-escape  of  any 
confined  air,  it  makes  a  gurgling,  bubbling  noise,  like  the  boiling  of  water,  but  much 


24  Casting  and  Foundixg — Brass  and  Bronze. 

louder,  and  it  will  sometimes  throw  the  fluid  metal  out  of  the  runner  in  3  or  4  separate 
spurts :  this  effect,  which  mostly  tjjoils  the  castings,  is  much  the  more  likely  to  occur 
•with  cored  works,  and  with  such  as  are  rammed  in  less  judiciously  hard,  without 
being,  like  the  moulds  for  fine  castings,  subsequently  well  dried.  The  moulds  are 
generally  openeil  before  the  castings  are  cold,  and  the  founder's  duty  is  ended  when  he 
has  sawn  off  the  ingates  or  ridges,  and  filed  away  the  ragged  edges  where  the  metal 
has  entered  the  seams  of  the  mould  ;  small  works  are  additionally  cleaned  in  a  rumble, 
or  revolving  cask,  where  they  soon  scrub  each  other  clean.  Nearly  all  small  brass 
works  are  poured  vertically,  and  the  runners  must  be  proportioned  to  the  size  of  the 
castings,  that  they  may  serve  to  fill  the  mould  quickly,  and  supply  at  the  top  a  mass  of 
still  fluid  metal,  to  serve  as  a  head  or  pressure  for  compressing  that  which  in  beneath,  to 
increase  the  density  and  soundness  of  the  casting.  Most  large  works  in  brass,  and  tiie 
greater  part  of  those  in  iron,  are  moulded  and  poured  horizontally. 

The  casting  of  figures  is  the  most  complex  and  difl3cult  branch  of  the  founder's  art. 
An  example  of  this  is  found  in  the  moulding  of  their  ornaments  in  relief.  The 
ornament,  whatever  it  may  be — a  monumental  bas-relief,  for  instance— is  first  modelled 
in  relief,  in  clay  or  wax,  upon  a  flat  surface.  A  sand-flask  is  then  placed  upon  the 
board  over  the  model,  and  well  rammed  with  sand,  which  thus  takes  the  impress  of  the 
model  on  its  lower  surface.  A  second  flask  is  now  laid  on  the  sunken  impression,  and 
also  filled  with  sand,  in  order  to  take  the  relief  impression  from  it.  This  is  generally 
termed  the  cope  or  back  mould.  The  thickness  of  the  intended  cast  is  then  determined 
by  placing  an  edging  of  clay  around  the  lower  flask,  upon  which  edging  the  upper  one 
rests,  thus  keeping  the  two  surfaces  at  the  precise  distance  from  each  other  that  it  is 
intended  the  thickness  of  the  casting  shall  be.  In  this  process,  the  metal  is  economized 
to  the  greatest  possible  extent,  as  the  interior  surface,  or  back  of  the  casting,  is  an  exact 
representation  of  the  relief  of  the  subject,  and  the  whole  is  thus  made  as  thin  in  every 
part  as  the  strength  of  the  metal  permits.  Several  modifications  of  the  process  just 
described  are  also  made  use  of,  to  suit  the  particular  circumstances  of  the  ease.  What 
has  been  said,  however,  is  a  detail  of  the  principle  pursued  in  all  matters  of  a  similar 
nature. 

Cores. — Following  are  instructions  for  a  composition  for  cores  that  may  be  required 
for  difficult  jobs,  where  it  would  be  extremely  expensive  to  make  a  core-box  for  the 
same :  Make  a  pattern  (of  any  material  that  will  stand  moulding  from)  like  the  core 
required.  Take  a  mould  from  the  same  in  the  sand,  in  the  ordinary  way,  place 
strengthening  wires  from  point  to  point,  centrally ;  gate  and  close  your  flask.  Then 
make  a  composition  of  2  parts  brickdust  and  1  of  plaster  of  Paris  ;  mix  with  water, 
and  cast.  Take  it  out  when  set,  dry  it,  ami  place  it  in  your  mould  warm,  so  that  there 
may  he  no  cold  air  in  it. 

Mahing  Bronze  Figures.  -It  is  a  singular  fact  that  melted  gold,  silver,  copper,  and 
iron,  if  jjourcd  hot  into  a  mould,  will  take  an  impression  of  all  the  details  of  the 
pattern  from  which  the  mould  was  made,  only  if  the  mould  is  made  of  sand.  Zinc 
can  be  moulded  in  copper  moulds,  and  that  is  the  principal  cause  of  the  low  price  of 
spelter  or  zinc  statuettes,  known  in  the  trade  as  imitation  or  French  bronze.  The  real 
bronze  is  an  alloy  of  copper,  zinc,  and  tin,  the  2  latter  metals  forming  a  very  small  part 
of  the  combination,  the  object  of  which  is  the  production  of  a  metal  harder  than  the 
pure  copper  would  be,  and  consequently  more  capable  of  standing  the  action  of  time, 
and  also  less  brittle  and  soft  than  zinc  alone  would  be.  Let  us  follow  a  statuette 
througli  the  different  processes  under  which  it  has  to  pass  from  the  time  it  leaves  the 
hands  of  the  artist  who  has  modelled  it  to  that  when  it  reaches  the  shop  where  it  is  to 
be  sold. 

The  original  statuette  is  generally  finished  in  plaster.  The  manufacturer's  first 
ooeration  is  to  have  it  cut  in  such  pieces  as  will  best  suit  the  moulder,  the  mounter, 
and  the  chaser,  for  very  few  statuettes  are  cast  all  in  one  piece.    Arms  and  leo-s  are 


Casting  and  Founding — Brass  and  Bronze.  25 

generally  put  on  after  the  body  is  finished.  The  next  operation  is  to  reproduce  the 
different  parts  of  the  figure  in  metal.  For  this  the  moulder  takes  it  in  hand  to  prepare 
the  moulil.  He  begins  by  selecting  a  rectangular  iron  frame,  technically  termed  a 
flask,  large  enough  for  the  figure  to  lie  in  easily.  To  this  frame,  -which  is  2  to  6  in, 
deep,  another  similar  frame  can  be  fastened  by  bolts  and  eyes  arranged  on  the  outside 
of  it,  so  that  several  of  these  frames  superposed  form  a  sort  of  box.  The  workman 
places  the  plaster  statuette,  which  is  now  his  "pattern,"  on  a  bed  of  soft  moulding-sand 
inside  the  first  iron  frame.  The  sand  used  for  mould  making  is  of  a  peculiar  nature,  its 
principal  quality  being  due  to  the  presence  of  magnesia.  One  locality  is  celebrated  for 
affording  the  best  sand — that  is  Fontenay-aux-Roses,  a  few  miles  from  Paris,  in  France. 
This  sand,  when  slightly  damp,  sticks  together  very  easily,  and  is  well  fitted  to  take  the 
impression  of  the  pattern. 

Once  the  pattern  is  embedded  in  the  sand,  the  workman  takes  a  small  lump  of 
sand,  which  he  presses  against  the  sides  of  the  figure,  covering  a  certain  portion  of  it. 
Next  to  this  piece  he  presses  another,  using  a  small  wooden  mallet  to  ensure  the  perfect 
adhesion  of  the  sand  to  the  pattern.  Each  one  of  these  pieces  of  sand  is  trimmed  ofl", 
and  a  light  layer  of  potato-flour  is  dusted  both  over  the  pattern  and  the  different  parts  of 
the  mould,  to  prevent  them  from  adhering  together.  In  course  of  time,  the  entire  part  of 
the  pattern  left  above  the  first  bed  of  sand,  on  which  it  has  been  placed,  will  be  covered 
with  these  pieces  of  sand,  which  are  beaten  hard  enough  to  keep  together.  Looae  sand 
is  now  thrown  over  this  elementary  brickwork  of  sand,  if  it  may  be  so  called,  and  a 
second  iron  frame  is  bolted  to  the  first  one  to  hold  the  sand  together,  which,  when  beaten 
down,  will  form  a  case  holding  the  elementary  sand  jjieccs  of  the  mould  in  place.  The 
workman  now  turns  his  mould  over,  removes  the  loose  sand  which  formed  the  original 
bed  of  the  pattern,  and  replaces  it  by  beaten  pieces,  just  as  he  had  done  on  the  upper 
side. 

It  can  now  easily  be  conceived  that  if  the  mould  is  opened  the  plaster  pattern  can 
be  removed,  and  that  if  all  the  pieces  of  sand  are  replaced  as  they  were,  there  will  be 
a  hollow  space  inside  the  mould,  which  will  be  exactly  the  space  previously  occupied  by 
the  pattern.  If  we  pour  melted  metal  into  this  space,  it  will  fill  it  exactly,  and  conse- 
quently, when  solidified  by  cooling,  reproduce  exactly  the  plaster  pattern.  For  small 
pieces,  this  will  answer  very  well ;  but  large  pieces  must  bo  hollow.  If  they  were  cast 
solid,  the  metal  in  cooling,  would  contract,  and  the  surface  would  present  cracks  and 
holes  difficult  to  fill.  To  make  a  casting  hollow  it  is  necessary  to  suspend  inside  the 
mould  an  inner  mould  or  "  core,"  leaving  between  it  and  the  inner  surface  of  the  first 
mould  a  regular  space,  which  is  that  which  will  be  filled  by  the  metal  when  it  is  poured 
in.  This  core  is  made  of  sand,  and  suspended  in  the  mould  by  cross  wires  or  iron  rods, 
according  to  the  importance  of  the  piece.  A  method  often  used  in  preparing  a  mould, 
named  by  the  French  cire  perdue,  will  help  to  illustrate  this.  The  artist  first  takes  a 
rough  clay  image  of  the  figure  he  wants  to  produce.  This  will  bo  the  core  of  the 
mould ;  he  covers  it  with  a  coating  of  modelling-wax  of  equal  thickness,  and  on  this 
wax  he  finishes  the  modelling  of  his  figure.  The  moulder  now  makes  his  sand 
mould  over  the  wax,  and,  when  it  is  completed  by  baking  the  mould  in  a  suitable 
furnace,  the  wax  runs  out,  leaving  exactly  the  space  to  be  filled  up  by  the  metal. 
The  celebrated  statue  of  Perseus,  by  Benvenuto  Cellini,  was  cast  in  this  way,  and  the 
method  is  very  frequently  employed  by  the  Japanese  and  Chinese.  Sometimes  flowers, 
animals,  or  baskets  are  embedded  in  the  mould,  and,  after  the  baking,  the  ashes  to 
which  they  have  been  reduced  are  either  washed  or  blown  out  to  make  room  for  tlie 
metal.  This  can  easily  be  done  through  the  jets  or  passages  left  for  the  metal  to  enter 
the  mould,  and  through  the  vent-holes  provided  for  the  escape  of  air  and  gases. 

When  the  mould  has  cooled,  it  is  broken  to  remove  the  casting  it  contains;  and 
here  is  the  reason  why  real  bronze  is  so  much  more  expensive  than  the  spelter 
imitation.     For  each  bronze  a  new  sand  mould  must  be  made,  while  the  zinc  or  siielter 


26  Casting  and  Founding — Brass  and  Bronze. 

can  be  poured  in  metallic  moulds,  which  will  last  for  ever.  In  this  way  the  pieces  are 
produced  with  but  little  more  labour  than  that  required  to  manufacture  leaden  bullets. 
These  pieces,  of  course,  do  not  receive  the  same  expensive  finish  as  the  real  bronze. 
When  the  casting  is  taken  out  of  the  mould,  it  goes  to  the  mounter,  who  trims  it  off, 
files  the  base  "  true/'  prepares  the  sockets  which  are  to  receive  the  arms  or  other  pieces 
to  be  mounted,  and  hands  the  piece  to  tlie  chaser.  The  work  of  this  artisan  consists  in 
removing  from  the  surface  of  the  metal  such  inequalities  as  tlie  sand  mould  may  have 
left,  and  in  finishing  the  surface  of  the  metal  as  best  suits  the  piece.  The  amount  of 
work  a  skilful  chaser  can  lay  out  on  a  piece  is  unlimited.  In  some  cases  the  very  tex- 
ture of  the  skin  is  reproduced  on  the  surface  of  the  metal.  This  mode  of  chasing, 
called  in  French  cliair^,  and  in  English  "skin-finish,"  is,  of  course,  only  found  on  work 
of  the  best  class.  Sometimes  pieces  are  finished  with  slight  cross-touches,  similar  to  the 
cross-hatching  of  engraving.  This  style  of  finish,  which  is  much  esteemed  by  connois- 
seurs, is  named  "  cross-ritSed,"  or  riboute.  After  the  chaser  has  finished  his  work,  the 
piece  returns  to  the  mounter,  who  definitively  secures  the  elements  of  the  piece  in  their 
places. 

The  next  process  it  that  of  bronzing.  The  colour  known  as  "  bronze  "  is  that  which 
a  piece  of  that  metal  would  take  through  the  natural  process  of  atmospheric  oxidation, 
if  it  were  exposed  to  a  dry  atmosphere  at  an  even  temperature.  But  the  manufacturer, 
not  being  able  to  wait  for  the  slow  action  of  nature,  calls  chemistry  to  his  aid,  and  by 
different  processes  produces  on  the  surface  of  the  piece  a  metallic  oxide  of  copper,  which, 
according  to  taste  or  fashion,  varies  from  black  to  red,  which  are  the  2  extreme  colours 
of  copper  oxide.  The  discovery  of  old  bronzes,  buried  for  centuries  in  damp  earth,  and 
covered  with  verdigris,  suggested  the  colour  known  as  vert  antique,  which  is  easily  pro- 
duced on  new  metal  by  the  action  of  acetic  or  sulphuric  acid.  In  the  15th  century, 
the  Florentine  artisans  produced  a  beautiful  colour  on  their  bronzes  by  smoking  them 
over  a  fire  of  greasy  rags  and  straw.  This  colour,  which  is  very  like  that  of  mahogany, 
is  still  known  as  Florentine  or  smoked  bronze.  Bronze  can  also  be  plated  with  gold 
and  silver,  nickel  and  platinum,  like  every  other  metal. 

On  this  subject,  Gornaud  says  that  the  manufacturer  of  art  bronzes  begins  by  giving 
the  style  and  general  proportions  to  the  artist,  who  is  his  first  and  most  important 
assistant.  The  artist  takes  the  clay,  the  model,  the  style,  and  arranges  it  into  its  varied 
forms ;  soon  the  architecture  is  designed,  the  figures  become  detached,  the  ornaments 
harmonize,  and  the  idea  embodied  in  the  outline  becomes  clear.  The  manufacturer, 
before  giving  his  model  to  the  founder,  should  indicate  with  a  pencil  the  parts  which 
ought  to  be  thickest,  lest  some  be  found  too  light,  without,  however,  altering  the  form  ; 
he  should  also  mark  the  parts  to  be  cut  in  the  mould  to  facilitate  putting  together.  Care 
must  be  taken  to  rub  with  hard  modelling  wax  all  the  projecting  parts  which  serve  to 
join  the  pieces,  so  that  the  turner  may  not  want  matter.  He  must  carefully  verify  all 
the  pieces  separately,  and  cover  with  wax  the  angles  and  ends  of  the  leaves — in  a  word 
the  weak  parts.  Generally  the  model  is  cast  in  half-red  bronze,  in  the  following  pro- 
portions (the  body  of  it  is  harder,  and  less  easy  to  work)  : — 

Copper      91-60  per  cent. 

Zinc 5-33 

Tin '.     '::  ■   1-70        „ 

Lead 1-37        „ 

Objects  destined  to  be  gilded  require  a  little  more  zinc  than  those  of  plain  bronze.  The 
models  just  described  serve  to  make  the  moulds  in  moulding  sand,  the  moulds  being 
afterwards  baked  in  a  stove  heated  to  572°  F.  (300°  C).  They  are  fastened  horizontally 
with  binding  screws,  in  order  to  run  in  the  bronze ;  the  temperature,  when  cast,  varies 
from  2732°  to  3272°  F.  (1500°  to  1800°  C). 

The  Japanese  word  corresponding  to  the  English  "  bronze  "  is  karaJcane,  which  means 


Casting  and  Founding — Brass  and  Bronze.  27 

"  Chinese  metal "  ;  -whereas  the  brass  alloys  are  called  sliin-cliu.  The  spelter  nsed  for 
the  latter  is  imported.  The  industry  of  bronze-casting  is  of  very  ancient  origin;  at 
first  foreign  metal,  imjwrted  either  from  China  or  Corea,  must  have  been  used,  as 
Japanese  copper  has  only  been  produced  since  the  beginning  of  the  Sth  century ;  by 
that  time,  however,  the  industry  of  bronze-casting  had  already  reached  a  certain  state 
of  perfection.  This  is  shown  by  the  fact  that  the  priest  Giyoki,  -who  lived  about 
this  time,  proposed  the  erection  of  a  monster  bronze  statue  of  Buddlia,  -which  was 
carried  into  effect.  There  -were  formerly  3  of  these  statues  in  Japan,  each  about  50  ft.  in 
height.  Other  specimens  of  large  bronze-castings  are  the  famous  bells  of  Nara,  Kiyoto, 
Nikko,  Shiba  in  Tokio,.and  others,  which  have  an  average  height  of  15  ft.  andaremoro 
than  10  ft.  in  diameter.  Statues  of  all  sizes,  bells,  vases,  water-basins,  candlesticks, 
incense-burners,  lanterns,  &c.,  have  been  manufactured  in  large  quantities  for  temples 
and  their  approaches.  Portrait- statues,  like  the  monuments  erected  in  foreign  countries 
to  honour  the  memory  of  celebrated  men,  have  never  been  made  in  Japan.  As  articles 
for  household  uses,  may  be  mentioned  fire-pots,  water-pots,  flower-vases  and  basins  in 
wliich  miniature  gardens  are  made,  perfume-burners,  pencil-cases,  small  water-pots 
of  fanciful  shapes  for  writing-boxes,  paper-weights,  and  small  figures  representing 
divinities.  These  bronze-castings  are  either  made  in  the  simple  and  severe  style  of  the 
old  celebrated  Chinese  bronzes,  or  else  are  specimens  of  the  peculiar  character  of 
Japanese  art,  which  chooses  it  subjects  from  natural  life,  either  combining  them  with 
lively  scenes  shewing  a  great  deal  of  humour,  together  with  the  most  minute  copying 
of  nature,  or  else  using  them  to  produce  some  artistical  effect.  The  bronze  is  cast  in 
clay  moulds  formed  upon  models  made  of  a  mixture  of  wax  and  resin,  which  is  melted 
out  from  the  finished  mould  previous  to  pouring  the  metal  in.  The  artist  who  makes 
the  model  generally  does  the  casting  himself,  and  in  most  cases  the  worksliops  consist 
only  of  the  master's  family  and  2  or  3  assistants.  The  melting  furnaces  are  of  exceed- 
ingly small  dimensions,  and  generally  made  of  an  iron  kettle  lined  with  clay.  After 
casting,  the  pattern  is  carefully  corrected  and  worked  out  by  chiselling,  but  the  best 
bronze-casters  prepare  the  model,  the  mould,  and  the  alloy  in  such  a  way  as  to  pro- 
duce castings  which  need  no  further  correcting  or  finishing.  In  some  cases  also  the 
whole  pattern  is  produced  merely  with  the  chisel  working  upon  a  smooth  surface ;  this, 
for  instance,  is  frequently  done  in  the  provinces  of  Kaga  and  Yechiu,  which  are  very 
important  centres  of  the  bronze  industry.  The  bronzing  of  the  pieces  is  done  in  many 
different  ways,  each  manufacturer  having  his  own  particular  process,  which  he 
modifies  according  to  the  composition  of  the  alloy  and  the  colour  he  wishes  to  produce. 
The  chemicals  used  for  this  purpose  are  very  few  in  number,  and  limited  to  vinegar, 
copper  sulphate,  and  verdigris  as  the  principal  substances  ;  other  materials,  used  less 
frequently,  consist  of  iron  sulphate,  red  oxide  of  iron,  and  lacquer.  It  may  be  added, 
as  a  peculiarity,  that  an  infusion  of  Eryantlms  tiiictorius  is  also  made  use  of  in  the 
bronzing  process. 

The  ornamentation  of  bronze  castings  is  not  only  produced  by  relief  patterns  moulded 
or  chiselled,  but  also  by  inlaying  the  objects  with  gold,  silver,  or  with  a  different  alloy. 
This  kind  of  workmanship  is  called  zogan,  and  is  principally  carried  on  in  the  provinces 
of  Knga  and  Yechiu.  The  process  by  which  the  inlaid  work  is  effected  differs  accord- 
ing to  the  nature  of  the  material  on  which  it  is  produced.  Sometimes  the  design  is 
hollowed  out  to  a  certain  depth  with  a  graver  or  chisel,  and  the  ornamenting  metal, 
silver,  gold,  &c.,  generally  in  the  shape  of  threads,  is  laid  into  the  hollow  spaces 
and  hammered  over,  should  the  alloy  be  soft  eneugh ;  the  edges  of  these  grooves 
are  first  slightly  driven  up,  so  that  when  the  silver  or  gold  has  been  laid  in,  they  can 
be  easily  hammered  down  again,  so  as  to  prevent  the  inlaid  metal  from  getting  loose.  Or 
else  the  surface  is  merely  covered  in  the  required  places  with  a  narrow  network  of  lines 
by  means  of  filing,  and  the  thin  gold  or  silver  leaf  fastened  on  to  tlus  rough  surface  by 
hammering.    This  last  process  is  the  one  used  mostly  for  inlaid  ii-on-work.    It  is  also 


28  Casting  and  Founding — Brass  and  Bronze.  _ 

said  that  the  design  is  often  produced  by  a  process  very  similar  to  that  of  the  so-called 
niello ;  only  instead  of  the  black  sulphuretted  silver  and  copper,  a  more  easily  fusible 
alloy  is  used.  Inlaid  work  of  the  above  kind  is  principally  made  in  Kaga  and  Yechiu, 
at  Kanasawa  and  Takaoko,  where  the  alloy  used  for  the  bronze-casting  is  mostly 
composed  of  copper,  tin,  zinc,  and  lead.  In  addition  to  the  castings,  the  repousse'  work 
should  be  mentioned,  by  which  mostly  small  metallic  ornaments  for  swords,  tobacco-  ^ 
pouches,  Ac,  and  also  larger  pieces,  such  as  tea-pots,  scent-burners,  vases,  &c.,  | 
are  produced;  the  inlaying  of  this  kind  of  ware  is  sometunes  of  extraordinary 
delicacy  and  beauty.  The  dark-blue  colour  shown  by  a  great  number  of  smaller 
pieces  is  that  of  the  shalcudo,  composed  of  copper,  and  3  and  4  per  cent,  of  gold. 
Finally,  attention  should  be  called  to  the  so-called  mohu-me,  a  word  which  might  be 
rendered  by  "  veins  of  the  wood.'  The  metal-work  designated  by  this  name  presents  a 
sort  of  damask  pattern  composed  of  variously-coloured  metals,  chiefly  white  silver,  red 
copper,  and  a  dark-blue  alloy.  Pieces  of  this  very  difHcult  sort  of  workmanship  are 
produced  by  overlaying  and  soldering  together  a  certain  number  of  plates  of  the  said  metals 
or  alloys,  by  hammering,  kneading,  resoldering,  filling  up  the  hollow  spaces  with  new 
metal,  and  repeating  these  operations  many  times  ;  finally,  when  stretched  out  into  a  thin 
sheet,  this  composition  shows  the  aforesaid  pattern  all  composed  of  veins  of  the  difierent 
metals  that  Lave  been  made  use  of. 

Cktsting  en  cire  perdue. — A  very  interesting  report  on  bronze-casting  in  Belgium, 
by  Sir  J.  Savile  Lumley,  has  recently  been  issued,  from  which  the  following  remarks 
are  abstracted. 

The  bronze  castings  made  under  the  First  Empire  were  from  moulds  made  on  plaster 
models  by  an  ingenious  method  known  by  the  name  of  ''  moulage  a  la  Fran^aise,"  which 
is  now  employed  in  all  French  bronze  foundries  ;  it  has  the  advantage  of  being  economical, 
especially  for  large  works,  and  is  generally  used  in  all  the  foundries  of  the  north  of 
Europe  ;  it  resembles  in  some  respects  the  system  practised  in  iron  foundries,  and  is  now 
employed  even  in  Italy  in  preference  to  the  wax  process. 

It  must  also  be  remarked  that  casting  "  en  cire  perdue  "  is  not  suitable  for  every  style 
of  sculpture  ;  works,  for  instance,  requiring  a  smooth  surface  can,  and  indeed  ought  to  be, 
cast  by  the  ordinary  French  system,  which  produces  metal  of  a  closer  grain  and  more 
polished  surface,  requiring,  however,  the  use  of  the  chasing  tool  over  the  whole  surface 
to  efiace  the  marks  left  by  the  joints  of  the  piece-mould,  and  the  entire  removal  of  what 
is  called  "  la  peau  de  la  fonte,"  the  casting  skin  or  "  epidermis  "  of  the  bronze  as  it 
comes  from  the  mould,  and  which,  in  the  wax  process,  constitutes  its  peculiar  charm, 
reproducing  as  it  does  a  perfect  facsimile  of  the  original  work  as  it  left  the  artist's  hands. 

The  ordinary  method  of  casting  is  more  suitable  to  tlie  bronze  articles  of  commerce 
which  require  reproduction,  as  well  as  for  bronzes  intended  to  be  gilt  or  silvered  and 
burnished.  The  wax  process,  on  the  contrary,  is  adapted  to  unique  artistic  works  not 
intended  for  reproduction  ;  the  casting  skin,  however,  so  dear  to  the  sculptor,  diminishes 
fco  a  certain  extent  the  beauty  of  the  artificial  "  patina,"  or  bronzing,  which  is  always 
more  brilliant  on  bronzes  that  have  been  worked  over  with  the  file  and  the  graving  tool. 
The  objection  manifested  by  motlem  bronze  founders  to  adopting  the  wax  process  has 
hitherto  been  tliat  in  case  of  failure  in  the  casting,  the  model  is  completely  lost ;  but 
by  a  m'-'thod  adopted  by  the  Brussels  Bronze  Co.,  failure  in  casting  confines  the  loss 
to  the  casting  itself,  and  leaves  the  original  model  intact  and  available  for  a  second 
attempt.  Following  is  a  technical  description  of  the  operations  carried  out  by  them  for 
bronze-casting  en  cire  perdue. 

Supposing  the  work  to  be  reproduced  to  be  the  portrait  bust  of  a  man  with  curly  locks 
and  a  long  ilowing  beard,  such  a  head  would  not  be  easy  to  cast  by  the  ordinary  process, 
owing  to  the  difficulty  of  conveying  the  liquid  bronze  into  the  cavities  of  the  curls  and 
the  interstices  of  the  beard,  but  tliis  is  easily  overcome  when  the  bust  is  cast  by  the  wax 
process.    The  different  operations  to  be  carried  out  are  as  follows :  (1)  The  production  of' 


Casting  and  Founding — Brass  and  Bronze. 


29 


the  model  in  plaster  or  terra-cotta  by  the  artist  sculptor.  (2)  Its  reproduction  in  wax  by 
the  founder.  (3)  The  repairing  and  retouching  of  the  wax  bust  by  the  artist  sculptor. 
(4)  The  preparation  for  casting  the  bust  before  forming  the  mould  and  cope.  (5)  The 
formation  of  the  mould.  (6)  Firing.  (7)  Casting.  (8)  Finishing  and  decorating  the 
bronze  bust.  Fig.  5  illustrates  the  arrangement  of  the  runners,  vents,  and  drains  :  a 
are  the  6  runners  by  which  the  molten  bronze  is  conveyed  into  the  mould ;   b,  vents  for 


tiie  escape  of  air  and  gases ;  c,  drains  for  carrying  off  the  melted  wax  ;  d,  vents  for  the 
escape  of  air  from  the  cores  within  the  bodies  of  the  horse  and  man.  All  except  d  are 
originally  of  wax  like  the  group  itself;  but  when  the  mould  is  fired,  the  wax  disappears, 
and  the  hollows  left  by  the  melted  wax  are  converted  into  bronze  and  have  to  be  sawn 
off. 

The  model. — The  bust  produced  by  the  sculptor,  which  may  be  in  terra-cotta  or 
plaster,  finished  as  far  as  the  artist  thinks  advisable,  is  handed  over  to  the  founder. 

Keproduction  in  wax.  This  requires  3  distinct  operations  :  A.  The  formation  of  a 
piece-mould.     B.  The  reproduction  of  the  bust  in  wax.    C.  Running  the  core. 

A.    Formation  of  a  piece-mould. — After   having  examined  the  bust  so  as  to   be 


30  Casting  and  Founding — Brass  and  Bronze. 

thoroughly  acquainted  "With  its  difBculties,  the  workman  proceeds  to  cut  off  with  a  twisted 
wire  the  projecting  portions  of  the  beard,  and  the  hair,  which,  from  the  cavities  of  the 
locks  and  curls,  would  present  difficulties  for  casting.  The  parts  thus  removed  are 
afterwards  easily  replaced.  The  bust  is  now  reduced  to  a  very  simple  instead  of  the 
complicated  form  it  at  first  presented.  The  plaster  mould  is  then  made  in  the  ordinary 
way :  the  bust  being  laid  on  a  table,  face  upwards,  is  fixed  in  that  iwsition  by  lumps  of 
modelling  clay  so  that  one-half  of  the  thickness  of  the  bust  is  completely  covered,  the 
remaining  lialf  presenting  the  appearance  of  a  figure  floating  on  its  back  in  water.  The 
workman  tlien  begins  to  make  the  pieces  of  the  mould :  taking  the  liquid  plaster,  which 
is  of  the  consistency  of  thick  cream,  he  forms  a  cube  2  in.  high,  and  the  same  length 
and  width,  which  he  squares  as  soon  as  the  plaster  begins  to  harden ;  with  this  cube  of 
plaster  he  covers  a  first  portion  of  the  surface  of  the  bust;  close  to  this  first  cube  a 
second  is  formed,  and  so  on  until  the  whole  bust  is  covered  with  an  irregular  mosaic  of 
plaster  cubes,  care  being  taken  to  prevent  them  'from  adhering  to  each  other  or  to  the 
bust  by  the  application  of  a  strong  solution  of  soap.  The  surface  of  these  cubes,  after 
being  well  wetted  with  this  solution,  is  covered  over  with  a  very  thick  coating  of  plaster, 
which  is  called  the  cope,  the  place  of  each  cube  having  been  previously  marked ;  the 
first  half  of  the  piece-mould  is  now  complete.  The  moulder  then  turns  the  bust  with 
the  face  down  on  to  the  table,  fixing  it  as  before,  and  proceeds  to  cover  the  back  in  the 
same  way  with  cubes  of  plaster,  so  that  when  this  second  half  is  also  covered  with  a 
thick  plaster  cope,  a  complete  mould  is  formed  in  2  halves.  The  great  art  of  the  moulder 
is  to  make  the  piece-moulds  at  the  same  time  simjile  and  solid,  and  fitting  so  closely 
together  as  to  leave  the  least  possible  trace  of  the  joints  on  the  plaster  cast  produced 
from  it ;  care  must  also  be  taken  that  in  handling  the  mould  none  of  the  small  pieces 
should  detach  themselves  from  it.  The  mould  being  completed,  it  is  opened,  that  is  to  say, 
the  2  plaster  coj^es  are  separated,  the  bust  which  is  intact  is  taken  out,  leaving  a  complete 
mould  in  which  other  busts  can  be  cast  just  as  bullets  are  cast  in  a  bullet-mould.  The 
next  operation  is  the  reproduction  of  a  bust  in  wax,  precisely  like  the  original  in 
jilastcr. 

B.  Eeproduction  in  wax. — One-half  of  the  piece-mould  is  jDlaced  on  the  table,  that 
is  to  say,  one  of  the  copes,  with  all  its  pieces,  and  the  mould  is  wetted  with  water  in  order 
to  prevent  the  wax  from  adhering  to  it ;  the  workman  then,  with  his  thumb,  presses  wax 
into  all  the  hollows  of  the  mould :  this  is  an  operation  of  considerable  delicacy.  The  wax. 
which  must  be  very  pure  and  malleable,  is  aifeeted  by  the  weather,  working  more  easily 
in  siuumer  than  in  winter  ;  the  most  suitable  quality  for  average  temperature  is  composed 
of  I  lb.  of  yellow  wax,  C-2  lb.  of  mutton  fat,  0-1  lb.  of  white  pitch,  melted  together  and 
coloured  a  deep  red  with  alkanet.  The  wax  pressed  into  the  mould  should  be  -jV  in. 
thick.  When  all  the  hollows  of  the  fii'st  cope  have  had  wax  of  the  requisite  thickness 
pressed  into  them,  the  same  process  is  applied  to  the  second  cope ;  the  two  copes,  on  being 
united,  form  a  complete  mould  ;  Ihey  are  then  tied  together  with  strong  cords,  and  the 
joints  of  ihe  copes  are  smeared  with  clay  so  that  the  mould  should  be  watertight.  In 
the  meantime  another  description  of  wax  of  harder  consistency,  composed  of  1  lb.  of 
yellow  wax,  1  lb.  of  resin,  and  ^  lb,  of  Venetian  turpentine,  has  been  melted  in  a  cnuldrou 
and  allowed  to  stand  on  the  fire  until  the  froth  has  subsided.  The  wax,  being  ready,  is 
left  to  cool  to  140°  or  158°  F,  (60°  or  70°  C),  when  it  is  poured  into  the  mould,  which 
it  fills,  and  is  allowed  to  remain  there  for  40  seconds ;  the  liquid  wax  is  then  poured  out 
of  the  mould  into  a  bucket  prepared  to  receive  it.  On  examining  the  interior  it  will  be 
found  that  the  soft  wax  which  was  pressed  into  the  mould  has  received  throughout  a 
coating  of  strong  wax  J  to  i-  in.  in  thickness,  making  an  entire  thickness  of  about  J  in.,' 
which  will  be  tlic  thickness  of  the  bronze  when  cast. 

C.  Formation  of  the  core.— The  core  is  the  substance  with  which  is  filled  the  hollow 
left  in  tlie  mould  after  the  liquid  wax  is  poured  out  of  it;  if  the  liust  were  cast  in  bronze 
without  a  core,  it  would  come  out  solid  and  weighing  10  or  15  times  heavier  than  is. 


Casting  and  Founding — Brass  and  Bronze.  31 

necessary,  and  the  casting  itself  would  be  faulty,  owing  to  the  great  shrinkage  produced 
by  such  a  mass  of  molten  metal,  wliich  would  also  have  the  efiect  of  vitrifying  the 
earths  forming  the  mould.  The  core  is,  in  fact,  indispensable  in  the  reproduction  of 
artistic  bronzes.  The  core  in  use  at  the  Brussels  Compagnie  des  Bronzes  is  formed  of  a 
mixture  consisting  of  2  parts  of  fine  plaster  of  Paris,  and  3  parts  of  a  pulverized  earth 
composed  of  quartz  sand,  thin  argillaceous  clay  with  traces  of  iron  oxide,  carbonate  of 
lime,  magnesia,  and  potash,  mixed  together  with  pure  water,  forming  a  liquid  paste 
which  is  called  "potin,"  and  which,  like  plaster  of  Paris,  hardens  very  rapidly. 

Having  calculated  the  capacity  of  the  hollow  left  by  the  wax,  a  quantity  of  "  potin," 
sufficient  to  fill  it,  is  prepared  and  poured  into  the  hollow,  leaving  enough  of  the  mixture 
to  form  a  pedestal  projecting  about  4  in.  from  the  bottom  of  the  bust  The  core,  having 
been  thus  poured  iuto  the  hollow,  is  left  to  harden. 

Before  proceeding  further  it  is  necessary  to  describe  the  means  by  which  an  escape  is 
provided  for  the  air  or  gases  of  the  core,  which,  if  not  set  free,  might  destrov  twist,  or 
otherwise  injure  the  bronze. 

This  is  effected  by  what  is  called,  in  the  language  of  the  foundry,  a  "  lanthorn  "  or 
chimney,  by  which  the  core  of  every  work  in  bronze  must  communicate  with  the  external 
air.  The  core  being  composed  of  porous  matter,  it  is  easy  to  understand  that  when  the 
molten  metal  enters  the  channel  prepared  for  it,  the  core  being  completely  isolated  and 
superheated,  the  gas  within  it  is  violently  dilated,  and  would  force  a  passage  through  the 
fused  metal  if  a  vent  were  not  prepared  for  it.  If,  owing  to  an  accident  or  faulty 
arrangement,  the  lanthorn  should  not  act,  the  bronze  figure  containing  the  core  would  be 
inevitably  bulged  and  distorted,  and  would  have  other  defects  which  would  considerably 
diminish  the  value  of  the  work. 

In  the  case  of  the  bust  already  described,  when  the  piece-mould  is  emptied  of  tho 
liquid  wax  that  has  been  poured  into  it,  and  just  as  the  "  potin  "  which  is  to  form  the 
core  is  about  to  be  jjoured  in,  a  round  stick,  about  |  in.  in  diameter,  having  a  pin  or  iron 
point  at  the  end,  after  being  well  oiled,  must  be  fixed  into  the  centre  of  the  hollow  of  the 
bust,  so  that  the  pin  should  project  through  the  wax  of  tlie  top  of  the  head.  The  stick 
must  be  held  in  this  position  while  the  "  potin  "  is  poured  in  round  tlie  stick,  and  when 
the  "  potin  "  begins  to  harden,  which  it  will  do  in  a  few  minutes,  the  stick  is  twisted  out, 
leaving,  of  course,  a  hollow  the  size  of  the  stick  traversing  the  bust  from  the  base  to  the 
head.  After  the  artist-sculptor  has  retouched  the  wax  bust,  the  mark  left  by  the  point 
of  the  stick  is  sought,  and  sufficient  wax  is  removed  round  it  to  23ermit  of  a  small  iron 
tube  of  the  same  diameter  as  the  hole  left  by  the  stick  being  forced  2  or  3  in.  deep 
into  the  head,  leaving,  however,  a  portion  projecting  from  the  head  and  beyond  the 
block-mould  when  it  is  formed  over  the  wax  bust. 

Any  crack  that  may  appear  between  the  tube  and  the  hole  is  carefully  closed,  and 
the  wax  is  retouched  where  the  tube  projects  from  the  head.  If  the  tube  were  not  forced 
sufficiently  into  the  head,  or  if  the  joint  were  not  properly  closed,  the  molten  bronze 
would  find  a  passage  and  fill  up  the  chimney  left  for  the  escape  of  air  from  the  core — 
an  accident  which  would  give  rise  to  efi'ects  like  those  above  referred  to.  In  complicated 
pieces  the  proper  formation  of  the  lanthorn  is  of  the  greatest  importance ;  it  is  often 
difficult  to  arrange,  and  requires  considerable  experience  to  make  and  place  it  properly. 
The  precise  proportions  of  the  earths  of  which  the  "  potin  "  is  composed  is  the  only  part 
of  the  process  concerning  which  any  reserve  is  'shown. 

The  mould  is  then  placed  on  the  table,  the  cords  are  unfastened,  the  clay  closing  the 
joints  of  the  2  copes  is  removed,  and  by  inserting  a  wedge  between  the  2  copes  the  upper 
cope  is  carefully  lifted  ofi".  The  workman  then  removes  one  by  one  all  the  little  pieces 
forming  the  mould,  exposing  the  corresponding  parts  of  the  bust  in  wax.  When  all  the 
pieces  are  removed  from  the  front,  the  bust  is  placed  upright  on  its  base  of  "  potin"  and 
the  cope  covering  the  back  is  then  removed  in  the  same  way,  together  with  the  pieces 
forming  the  mould.    These  pieces  are  then  carefully  returned  to  the  cope  each  in  its 


32  Casting  and  Founding — Brass  and  Bronze. 

place,  and  the  mould  when  put  together  again  is  ready  to  be  used  for  another  was  bust 
when  reijuired. 

The  bust  now  appears  in  wax  reproducing  exactly  the  original  bust  in  clay,  with  the 
exception  of  the  seams  from  the  joints  of  the  mould,  which  are  then  removed  by  the 
artist-sculptor  himself.  Although  wax  is  neither  as  easy  nor  as  pleasant  a  material  to 
work  iu  as  modelling-clay,  a  very  short  time  suffices  to  enable  the  sculptor  to  manipulate 
it  with  facility,  and  an  opportunity  is  afforded  him  of  giving  the  finishing  touches  to  his 
work  with  still  greater  delicacy  than  in  clay. 

It  is  at  this  period  that  the  beard  and  curls  of  the  hair  which  were  removed  before 

I      making  the  mould,  and  which  have  been  separately  reproduced  in  wax  by  the  same 

process,  arc  fixed  in  their  respective  positions  by  iron  points  which  are  driven  through 

the  wax  into  the  solid  core  and  hold  the  pieces  firmly  in  their  places;  the  artist  then 

going  over  the  joints  with  a  modelling  tool  renders  them  invisible. 

Tietouching  the  wax  bust.— The  great  advantage  of  reproducing  the  bust  in  wax  is 
that  it  enables  the  artist  to  work  upon  it  so  that  the  wax  bust  is  not  only  equal  to  the 
original  in  plaster  or  terra-cotta,  but  may  become  even  superior  to  it,  for  the  artist  on 
seeing  his  work  in  a  material  of  another  colour,  and  after  a  certain  time,  may  discover 
certain  faults  which  he  can  correct  in  the  wax,  or  if  he  thinks  it  necessary  he  can  make 
6uch  alterations  as  he  may  consider  advisable. 

Preparing  the  bust  before  making  tlie  casting  mould  or  cope. — The  bust  in  wax, 
having  been  looked  over  and  corrected  by  the  artist,  is  now  placed  in  the  hands  of  the 
founder,  who  begins  by  building  a  layer  of  fire-bricks  of  the  size  required  for  the  object 
that  is  to  be  cast;  this  layer,  for  a  bust,  may  be  3  ft.  by  2  ft.  4,  iu.  and  9  iu.  in  height 
above  the  floor  of  the  atelier.  "When  ready  the  wax  bust  is  placed  upon  it  on  its  pedestal 
of  "potin,"  and  firmly  fixed  to  the  brick  layer  or  base.  The  next  operation  is  one  of 
considerable  delicacy,  namely,  the  placing  of  the  runners  or  channels  to  enable  the 
liquid  bronze  to  flow  through  and  fill  up  the  vacant  space  left  by  the  melted  wax,  and 
the  vents,  which  are  other  channels  for  the  escape  of  the  air  and  gas  driven  out  of  the 
hollow  by  the  force  of  the  liquid  metal. 

For  a  bust  the  placing  of  these  channels  is  not  difficult,  but  when  a  complicated  work 
— a  group  or  a  large  bas-relief — has  to  be  prepared  for  casting,  the  proper  position  of 
these  channels  requires  considerable  study,  for  if  one  of  them  should  be  badly  placed  it 
would  compromise  the  success  of  the  casting. 

In  order  to  make  a  runner  for  the  bust  in  question,  a  stick  of  wax  is  used  2  ft.  long 
with  a  diameter  of  If  in.,  one  end  of  which  is  cut  or  flattened  into  the  shape  of  the 
mouthpiece  of  a  whistle  ;  the  other  end  is  considerably  thickened  by  the  addition  of  wax 
until  it  has  the  form  of  a  funnel;  it  is  then  bent  into  the  form  of  a  double  siphon  with 
the  2  parallel  branches  considerably  lengthened.  Having  thus  prepared  the  runner,  in 
order  to  fix  it,  3  or  4  tliin  iron  pins  are  driven,  in  a  straight  line,  at  a  distance  from  each 
other  of  ^  in.,  into  one  shoulder  of  the  bust,  from  which  they  are  allowed  to  project 
about  1  or  1 2  in. ;  upon  these  is  pressed  the  flattened  end  of  the  runner,  and  the  joint 
whore  it  touches  the  shoulder  is  then  closed  with  wax,  which  is  melted  with  a  heated 
tool,  tlms  increasing  the  solidity  of  the  joints.  The  vent,  which  is  fastened  in  the  same 
way  on  the  other  shoulder,  is  a  simple  straight  stick  of  wax,  thinner  than  that  of  the 
runner,  also  with  the  flattened  end  touching  the  shoulder. 

If  from  any  cause  the  runner  and  the  vent  are  not  firm  in  their  positions,  another 
iron  pin  is  driven  into  the  top  of  the  head  of  the  bust,  and  the  runner  and  vent  are 
fastened  to  it  with  packthread. 

The  founder  has  now  before  him  the  bust,  surmounted  by  the  runner  and  the  vent 
rising  from  the  shoulders  to  the  summit  of  the  head,  like  little  chimneys,  to  the  height 
of  G-8  in. ;  he  then  proceeds  to  drive  a  number  of  iron  pins  all  over  the  surface  of  the 
bust,  through  the  wax,  into  tlie  core,  the  object  of  which  is  to  maintain  the  core  in  its 
place ;  these  pins  must  project  one-half  their  length  from  the  surface  of  the  bust. 


Casting  and  Founding — Brass  and  Bronze.  33 

Formation  of  the  casting  mould  or  cope. — The  bust  thus  prepared  is  placed  on  the 
brick  layer  in  the  place  in  which  it  is  to  be  fired  ;  it  is  tlien  surrounded  Ijy  a  wooden 
case,  having  the  form  of  a  4-sided  truncated  pyramid.  This  case,  -which  must  bo 
suiRciently  large  to  leave  a  space  of  6-8  in.  between  it  and  the  greatest  projection  of  the 
bust,  is  made  of  frames  placed  one  upon  the  other,  i)  in.  in  height,  the  whole,  when 
placed  together,  having  the  form  of  a  pyramid;  the  first  frame,  namely  that  whicli  rests 
on  the  brick  layer,  being  naturally  the  largest.  The  case  being  ready,  the  cube  measure 
of  its  capacity  is  calculated,  and  the  upper  frames  are  removed,  leaving  only  the  lower 
one  resting  on  the  brick  layer.  The  mould  is  made  of  precisely  the  same  material  as 
that  forming  the  core  of  the  wax  bust ;  the  requisite  quantity  is  prepared  as  well  as  the 
proper  number  of  measures  of  water  required  for  mixing  the  "  potin."  As  the  operation 
of  filling  the  frames  must  proceed  rapidly,  and,  once  begim,  cannot  be  stopped,  care  must 
be  taken  to  have  a  sufficient  supply  of  the  material  at  hand.  For  the  formation  of  the 
cope  of  a  large-sized  bust,  3  men  are  required  for  mixing  the  "  potin,"  2  for  pouring  it 
into  the  frames,  and  2  for  throwing  the  mixture  on  to  the  bust,  which  is  done  with 
painters'  brushes,  and  in  such  a  way  as  to  thoroughly  fill  up  all  the  cavities  of  tlie 
sculpture. 

The  3  mixers  have  each  before  them  a  vat  or  bucket  containing  one  measure  of  water, 
into  which  they  pour  rapidly  the  dry  "  potin,"  which  is  in  the  form  of  fine  sand  or 
powder,  and  this  not  all  at  once,  but  gradually,  by  allowing  it  to  fall  through  their 
fingers;  when  the  "jiotin"  is  all  in  the  water,  the  men  work  it  into  a  jiaste  with  their 
hands.  As  soon  as  it  is  ready,  the  other  men  pour  one  after  the  other  the  contents  of 
the  3  vats  or  buckets  into  the  lower  frame  of  the  wooden  case;  in  the  meantime  tiie 
mixers  are  preparing  fresh  vats  of  "  potin."  As  soon  as  the  first  frame  is  nearly  filled, 
the  second  frame  is  placed  above  it,  the  joints  being  closed  with  "potin"  that  has 
become  almost  hard,  and  it  is  filled  in  the  same  way ;  at  the  same  time  the  other  2  men, 
armed  with  brushes,  have  been  sprinkling  the  bust  with  the  mixture  so  as  to  fill  up 
completely  all  the  cavities  of  the  wax  bust;  if  this  is  not  done  with  great  care  and 
exactitude,  any  cavity  that  is  not  filled  with  "  potin  "  will  retain  a  certain  quantity  of 
air,  and  when  cast  the  cavity  will  be  entirely  filled  up  with  a  solid  mass  of  bronze  which 
would  require  to  be  removed  by  the  chaser  at  a  considerable  expense,  or  it  may  happen 
that  the  fault  is  one  impossible  to  remedy.  When  all  the  frames  have  been  placed  one 
upon  the  other  and  filled  with  "  potin,"  the  operation  is  completed,  care  having  been 
taken  to  fill  the  upper  frame  only  to  the  level  of  the  tojj  of  the  runner  and  the  vent,  so  as 
not  to  cover  them. 

A  third  channel,  required  for  draining  off  the  melted  wax,  is  formed  in  the  same  way 
as  the  other  two,  a  stick  of  wax  1^  in.  in  diameter  being  placed  at  the  base  of  the  bust 
on  the  slant,  so  as  to  facilitate  the  issue  of  the  liquid  wax,  the  stick  of  wax  being 
fastened  by  one  end  to  the  wax  of  the  bust,  while  the  other  end  touches  the  wood 
which  forms  the  case.  The  "  jjotiu  "  having  been  allowed  to  harden,  which  it  does  very 
rapidly,  the  wooden  frames  are  removed,  and  the  cope  appears  in  the  form  of  a  block  of 
stone,  on  the  upper  surface  of  which  is  seen,  on  the  right  the  wax  of  the  runner,  and  on 
the  left  that  of  the  vent,  and  at  the  base  that  of  the  drain. 

Firing. — The  block  is  now  ready  for  firing.  A  furnace  of  fire-bricks  is  built  round  it, 
2  chimneys  being  placed  on  the  runner,  and  the  vent  communicating  with  the  outer 
air,  and  round  this  furnace  a  second  is  built,  in  which  a  coke  fire  is  lighted.  The  fire 
should  be  moderate  at  first,  gradually  increasing  until  the  mass  is  baked  throughout,  so 
that  it  is  completely  red-hot  to  the  very  centre.  After  baking  for  6  hours,  the  block  is 
sufficiently  heated  to  cause  the  wax  to  melt ;  this  then  escapes  through  the  drain,  which 
is  in  connection  with  an  iron  tube  passing  through  the  2  furnaces,  and  communicating 
with  a  vat  into  which  the  wax  flows.  When  the  wax  has  ceased  to  flow,  the  opening 
from  the  drain  must  be  carefully  closed,  in  order  to  prevent  any  air  from  reaching  the 
interior,  which  would  be  injurious  to  the  process. 

D 


34  Casting  and  Founding — Brass  and  Bronze. 

After  30  hours*  firing,  puffs  of  blue  smoke  arc  seen  issuing  from  the  chimneys.  This 
shows  that  the  heat  ia  sufficiently  intense  to  cause  the  evaporation  of  any  wax  that  may 
liuvfi  remained  in  the  block.  After  GO  or  70  hours  the  smoke  changes  from  blue  to  a 
reddish  hue;  this  shows  tliat  the  wax  is  completely  destroyed.  The  smoke  is  succeeded 
by  a  slight  watery  vapour,  and  the  fire  is  increased  until  all  moisture  has  disappeared. 
This  is  ascertained  by  placing  a  cold  steel  plate  over  the  orifice,  upon  which  the  slightest 
vapour  shows  itself  in  the  form  of  a  veil  or  dewlike  drops.  If  at  this  moment  it  were 
l)0ssible  to  look  into  the  centre  of  the  block,  it  would  be  found  to  be  of  a  deep  red.  When 
all  symptoms  of  moisture  luivc  disapi^eared,  the  fire  is  covered  up,  no  further  fuel  is  added, 
and  the  fire  goes  out  gradually.  ■ 

The  exteiiial  furnace  is  pulled  do%Yn  as  soon  as  the  bricks  have  cooled  sufficiently  to" 
enable  the  woikmen  to  do  so  without  burning  themselves ;  and  in  order  to  hasten  the 
cooling  of  the  block  some  of  the  bricks  forming  the  cover  of  the  interior  furnace  are 
also  removed.  Later  this  is  also  demolished,  and  the  moulding  block  is  allowed  to  cool. 
In  a  -word,  it  is  necessary  to  proceed  gradually  for  the  purpose  of  cooling  as  well  as  for 
that  of  firing,  sudden  changes  of  temperature  being  fatal,  and  the  success  of  the  operation 
depending  in  great  part  on  the  regularity  of  the  jirocess. 

The  firing  being  now  finished,  the  block  has  the  same  appearance  as  before,  only 
in  renioving  the  chimneys  the  runner  and  the  vent  are  found  to  be  replaced  by  holes 
or  channels,  while  another  hole  will  be  found  at  the  base  in  the  place  of  the  wax  drain. 
Tiie  wax  ia  melting  has  formed  these  channels,  and  has  left  a  hollow  space  throughout 
the  block  between  the  core  and  the  mould.  Keference  has  been  made  above  to  the 
use  of  iron  pins  pressed  into  the  wax  bust.  As  long  as  the  core,  the  wax,  and  the 
mould  Iiad  not  been  submitted  to  the  action  of  the  fire  they  formed  a  solid  mass,  but 
with  the  melting  of  the  wax  the  core  has  become  isolated,  and,  as  it  is  formed  of 
exceedingly  friable  earth,  the  least  motion  might  throw  it  down  and  break  it ;  this 
inconvenience  is  avoided  by  the  employment  of  the  pins  above  referred  to,  which, 
jienetratiiig  through  the  wax,  on  the  one  hand  into  the  core  and  on  the  other  into  the 
mould,  render  the  core  immovable  even  after  the  disappearance  of  the  wax. 

The  casting  in  bronze. — This  is  the  last  operation.  The  block  having  become 
sufficiently  cool,  it  is  surrounded  with  iron  frames  placed  one  above  the  other ;  the  space 
between  tlie  block  and  the  frames  is  filled  by  pressing  into  it  ordinary  moulding  earth. 
This  operation  requires  the  greatest  care;  its  object  is  to  prevent  the  block  from 
bur.-^ting  when  the  liquid  bronze  is  poured  into  it  by  the  pressure  of  the  gas  and  the 
expansion  of  the  air  while  the  fused  metal  is  flowing  through  the  mould,  a  comparatively 
small  quanfity  of  metal  in  fusion  being  capable  of  producing  effects  of  incredible  force 
whicli  it  is  difficult  to  account  for. 

Tlie  block  being  perfectly  iron-bound,  a  basin  of  iron  covered  with  baked  clay  and 
I'ierced  witli  a  conical  funnel  is  placed  over  the  runner  and  closed  with  an  iron  stopper, 
from  Avhich  projects  a  long  stem.  The  hole  of  the  basin  communicates  directly  with 
that  of  the  runner ;  the  opening  of  the  vent  is  left  fi-ee,  but  in  front  of  it  a  small  basin 
is  hollowed  out  of  the  block.     Everything  is  now  ready  for  the  casting. 

If  the  bust  is  calculated  to  weigh  50  lb.,  SO  lb.  of  bronze  are  put  into  tlie  melting- 
pot  in  order  to  be  certain  of  having  enough  metal,  and  it  is  necessary  to  allow  for  the 
runner,  tlie  veiit,  and  the  drain.  The  bronze  which  has  hitherto  given  the  best  results 
is  composyd  as  follows  : — 70  lb.  rod  copper,  28  lb.  zinc,  2  lb.  tin. 

Tlie  bronze  being  sufficiently  melted,  the  crucibles  are  lifted  out  of  the  furnace 
and  are  eini)tied  into  the  basin  above  referred  to  ;  a  workman  at  the  word  of  command 
takes  out  the  iron  stopper,  the  molten  bronze  flows  into  the  runner,  penetrates  into  the 
mould,  fills  up  all  the  hollows,  and  returns  to  its  level,  the  surplus  metal  flowing  out 
at  the  vent  into  tiie  basin  that  has  been  hollowed  out  of  the  block  to  receive  it, 
preceded  by  the  air  and  gas  driven  out  by  the  entry  of  the  metal. 

If  the  oper.diou  lias  been  made  without  producing  noise,  the  casting  may  be  cott- 


Casting  and  Founding — Iron,  35 

sidered  to  have  been  successful,  but  notwithstanding  all  the  care  taken  to  attain  success, 
some  fault  may  have  occurred.  The  natural  curioaity  to  learn  tlio  result  may  soon  be 
satisfied,  for  in  J  hour  the  metal  will  have  cooled  sufficiently  to  allow  the  block  tobe 
broken  up. 

The  workmen  begin  by  lifting  off  the  iron  frames,  and  then,  removing  the  earth 
that  was  pressed  round  it,  commence  to  break  up  the  block  with  iron  picks,  proceeding 
with  precaution,  and  as  soon  as  any  portion  of  the  bronze  shows  itsulf  the  picks  are 
laid  aside  for  smaller  and  lighter  tools,  with  which  the  "  potin  "  that  surrounds  and 
conceals  the  work  is  at  length  removed,  the  bust  gradually  appears,  and  it  is  possible 
to  judge  whether  the  casting  has  been  successful ;  the  bust  itself,  however,  is  covered 
with  a  white  crust  from  the  "potin"  still  adhering  to  it,  and  which  only  partially 
detaches  itself.     To  get  rid  of  this  crust  entirely  is  a  work  of  some  time. 

The  runner,  the  vent,  and  the  drain,  which  have  been  transformed  by  the  casting 
into  solid  bronze,  are  now  sawn  off,  the  core  inside  the  bust  is  broken  up,  and  the 
bust  is  emptied ;  it  is  then  placed  for  several  hours  in  a  bath  of  water  and  sulphuric 
acid,  and  when  taken  out  is  vigorously  scrubbed  with  hard  brushes,  rinsed  in  clean  water, 
and  allowed  to  dry.  The  bust  is  now  handed  over  to  the  chasers,  who  efface  the  traces 
left  by  the  runners  and  vents,  remove  any  portions  of  metal  that  may  fill  up  the  cavities 
into  which  the  "  potin  "  has  not  penetrated,  stop  up  with  bronze  the  little  holes  left  by 
the  iron  pins,  and  in  fact  place  the  work  in  a  perfect  state,  leaving,  however,  untouched 
the  epidermis  of  the  bronze,  for  in  this  consists  the  merit  and  value  of  the  "cire 
perdue  "  process,  which  renders  so  completely  every  touch  of  the  artist  that  it  seems  as 
if  he  had  kneaded  and  worked  the  bronze  with  his  fingers. 

The  bust,  now  completed,  is  placed  in  the  hands  of  the  bronze  decorators,  who  give 
it  a  "  patiua  "  in  imitation  of  that  produced  by  oxidation ;  the  colour  generally  preferred 
for  portrait  busts  is  tlie  brown  tone  of  the  Florentine  bronzes.  This  artificial  "  patina" 
can  be  produced  in  a  great  variety  of  tones,  light  or  dark,  but  in  every  case  it  is 
preferable  that  a  well-modelled  work  should  have  a  dead  unpolished  surface.  The 
decoration  of  a  bronze  work  is  a  question  of  taste  or  fashion  for  which  there  is  no  rule, 
though  no  doubt  for  many  the  success  of  a  work  depends  very  often  on  its  decoration. 

Iron  Founding. — The  following  observations,  while  bearing  more  or  less  on 
casting  generally,  refer  more  particularly  to  the  art  of  the  ironfoundcr. 

The  first  consideration  is  the  pattern  from  which  the  moulding  is  to  be  made, 
the  planning  of  which  necessitates  a  knowledge  of  shrinkage  and  cooling  strains  in 
heated  metal.  Founding  oi:)erations  are  divided  into  2  classes,  known  technically  as 
green  sand  moulding  and  loam  or  dry  sand  moulding:  the  first,  when  patterns  or 
duplicates  are  used  to  form  the  moulds ;  the  second,  when  the  moulds  are  built  by  hand 
without  the  aid  of  complete  patterns.  Founding  involves  a  knowledge  of  mixing  and 
melting  metals  such  as  are  used  in  machine  construction,  the  preparing  and  setting  of 
cores  for  the  internal  displacement  of  the  metal,  cooling  and  shrinking  strains,  chills, 
and  many  other  things  that  are  more  or  less  special,  and  can  only  be  learned  and  under- 
stood from  actual  observation  and  practice. 

Patterns. — The  subjoined  remarks  on  the  conditions  to  be  considered  in  pattern- 
making  are  condensed  from  Eichards'  valuable  manual  on  '  "Workshop  Manipulation,' 
which  is  more  than  once  referred  to  as  an  indispensable  companion  for  the  intelligent 
worker  in  metals.    He  enumerates  the  following  points : — 

(1)  Durability,  choice  of  plan  and  cost.  Consider  the  amount  of  use  that  the  patterns 
are  likely  to  serve,  whether  they  are  for  standard  or  special  machines,  and  the  quality 
of  the  castings  so  far  as  affected  by  the  patterns.  A  first-class  pattern,  framed  to 
withstand  moisture  and  rapping,  may  cost  twice  as  much  as  another  that  has  the  same 
outline,  yet  the  cheaper  pattern  may  answer  almost  as  well  to  form  a  few  moulds. 

(2)  Manner  of  moulding,  and  expense,  so  far  as  determined  by  tlio  patterns.  These 
last  may  be  parted  so  as  to  be  "  rammed  up  "  on  fallow  boards  or  a  level  floor,  or  the 

D  2 


36  Casting  and  Founding — Iron. 

patterns  may  be  solid,  and  have  to  be  bedded,  as  it  is  termed ;  pieces  on  tiie  top  may 
be  made  loose,  or  fastened  on  so  as  to  "cope  oft";"  patterns  may  be  well  linisbed  so 
as  to  draw  clean,  or  rough  so  that  a  mould  may  require  a  great  deal  of  time  to  dress  up 
after  a  pattern  is  removed. 

(3)  Tlie  soundness  of  such  parts  as  are  to  be  planed,  bored,  and  turned  in  finishing. 
Determined  mainly  by  how  the  patterns  are  arranged,  by  which  is  the  top  and  which 
the  bottom  or  drag  side,  the  manner  of  drawing,  and  provisions  for  avoiding  dirt  and  slag. 
(■i)  Cores,  where  used,  how  vented,  how  supported  in  the  mould,  and  how  made. 
Cores  of  irregular  form  are  often  more  expensive  than  external  moulds,  including  the 
patterns ;  the  expense  of  patterns  is  often  greatly  reduced,  but  is  sometimes  increased, 
by  the  use  of  cores,  which  may  be  employed  to  cheapen  patterns,  add  to  their  durability, 
or  ensure  sound  castings. 

(.^)  Shrinkage.  This  is  tlie  allowance  that  has  to  be  made  for  the  contraction  of 
castings  in  cooling,  i.  e.  the  ditference  between  the  sizes  of  the  pattern  and  the  casting — 
a  simple  matter  apparently,  which  may  be  provided  for  in  allowing  a  certain  amount  of 
shrinkage  in  all  directions;  but  when  the  inequalities  of  shrinkage  both  as  to  time  and 
degree  are  taken  into  account,  the  allowance  to  be  made  becomes  a  problem  of  no  little 
complication. 

((J)  Inherent,  or  cooling  strains.  They  may  either  spring  and  warp  castings,  or 
weaken  them  by  maintained  tension  in  certain  parts — a  condition  that  often  requires  a; 
disposition  of  the  metal  quite  ditferent  from  what  working  strains  demand. 

(7)  Draught.  The  bevel  or  inclination  on  tlie  sides  of  patterns,  to  allow  them  to  be 
withdrawn  from  the  moulds  without  dragging  or  breaking  the  sand. 

For  most  ordinary  purposes,  patterns  are  made  of  wood ;  but  in  very  heavy  parts  of 
machinery,  such  as  pulleys  and  gear  wheels,  iron  patterns  are  preferable.  As  there 
must  be  always  a  proportion  of  loose  sand  and  "  scrutf "  in  a  casting,  it  is  important  to 
arrange  the  pattern  so  that  this  part  shall  come  in  the  least  disadvantageous  position. 
Thus  the  top  of  a  mould  or  "  cope  "  contains  the  dirt,  while  the  bottom  or  "  drag  side  " 
is  generally  clean  and  sound :  the  rule  is  to  arrange  patterns  so  that  the  surfaces  to- 
be  finished  will  come  on  the  drag  side.  Expedients  to  avoid  dirt  in  such  castings  as 
are  to  be  finished  all  over,  or  on  2  sides,  are  various.  Careful  moulding  and  washing, 
to  remove  loose  sand,  is  the  first  requisite ;  sinking  heads,  that  rise  above  the  moulds-, 
are  commonly  employed  when  castings  are  of  a  form  which  allows  the  dirt  to  collect  at 
one  point.  The  quality  of  castings  is  governed  by  many  other  conditions,  such  as  the 
manner  of  "gating"  or  flowing  the  metal  into  the  moulds,  the  temperature  and  quality 
of  the  iron,  the  temperature  and  character  of  the  mould. 

Cores  are  employed  mainly  for  the  displacement  of  metal  in  moulds ;  they  may 
be  of  green  sand,  and  made  to  surround  the  exterior  of  a  piece,  as  well  as  to  make 
perforations  or  to  form  recesses  within  it.  The  term  "core,"  in  its  technical  sense, 
means  dried  moulds,  as  distinguished  from  green  sand :  thus,  wheels  or  other  castings 
are  said  to  be  "  cast  in  cores  "  when  the  moulds  are  made  in  pieces  and  dried.  Sup- 
porting and  venting  cores,  and  their  expansion,  are  conditions  to  which  especial  attention 
is  needed.  When  a  core  is  surrounded  with  hot  metal,  it  gives  ofl",  because  of  moisture 
and  the  burning  of  the  "  wash,"  a  large  amount  of  gas  which  must  liave  free  means  of 
escape.  In  the  arrangement  of  cores,  therefore,  attention  must  be  had  to  some  means  of 
venting,  which  is  generally  attained  by  allowing  them  to  project  through  the  sides  of 
the  mould  and  communicate  with  the  air  outside.  The  venting  of  moulds  is  even  more 
important  than  venting  cores,  because  core  vents  only  carry  oif  gas  generated  within 
the  core  itself,  while  the  gas  from  its  exterior  surface,  and  from  the  whole  mould,  has 
to  find  means  of  escaping  rapidly  from  the  flasks  when  the  hot  metal  enters.  If  it  were 
not  for  tiie  porous  nature  of  sand  moulds,  they  would  be  blown  to  pieces  as  soon  as  the 
hot  metal  entered  them ;  both  because  of  the  mechanical  expansion  of  the  gas,  and  often 
from  explosion  by  combustion.     But  for  securing  vent  for  gas,  moulds  could  be  made 


Casting  and  Founding — Iron.  37 

from  plastic  material,  so  as  to  produce  fine  castings  .with  clear  sharp  outlines.  Tho 
means  of  supporting  cores  consist  of  "  prints "  and  "  anchors."  Prints  are  extensions 
of  the  cores,  which  project  through  the  casting  and  into  the  sides  of  the  mould,  to  bo 
held  by  the  sand  or  flask.  They  have  duplicates  on  the  patterns,  called  "  core  prints," 
whicli  should  be  of  a  diflerent  colour  from  the  patterns.  The  amount  of  surface 
required  to  support  cores  is  dependent  upon  their  cubic  contents,  because  the  main 
force  required  is  to  hold  them  down,  and  not  to  bear  their  weight :  tho  floating  force  of  a 
core  is  as  the  difltrence  between  its  weight  and  that  of  a  solid  mass  of  metal  of  tho  same 
size.  When  it  is  impossible,  from  the  nature  of  castings,  to  have  prints  large  enough 
to  support  the  cores,  this  is  efl"ected  by  anchors, — pieces  of  iron  that  stand  like  braces 
between  the  cores  and  the  flasks  or  pieces  of  iron  imbedded  in  the  sand  to  receive  the 
strain  of  the  anchors.  Cores  expand  when  heated,  and  require  an  allowance  in  their 
dimensions  the  reverse  from  patterns,  especially  when  the  cores  are  made  upon  iron 
frames.  For  cylindrical  cores  less  than  6  in.  diam.,  or  less  than  2  ft.  long,  expansion 
need  not  be  taken  into  account  by  pattern-makers,  but  for  large  cores  careful  calculation 
is  required. 

Shrinkage,  or  the  contraction  of  castings  in  cooling,  is  provided  for  by  adding  -^  in. 
to  i  in.  to  each  foot  in  the  dimensions  of  patterns.  This  is  accomplished  by  employing  a 
shrink  rule  in  laying  down  pattern-drawings  from  the  figured  dimensions  of  the  finished 
work.  Inlierent  or  cooling  strains  is  a  much  more  intricate  subject.  They  may  weaken 
castings,  or  cause  them  to  break  while  cooling,  or  sometimes  even  after  they  are  finished; 
and  must  bo  carefully  guarded  against,  both  in  the  preparation  of  designs  and  the 
•arrangements  of  patterns,  especially  for  wheels  and  pulleys  with  spokes,  and  for  struts 
or  braces  with  both  ends  fixed.  The  main  difiiculty  resulting  is  that  of  castings  being 
warped  and  sprung  by  the  action  of  unequal  strains,  caused  by  one  part  cooling  or 
"  setting  "  sooner  than  another.  This  may  be  the  result  of  unequal  conducting  power  in 
■difi"erent  parts  of  a  mould  or  cores,  or  it  may  arise  from  the  varying  dimensions  of  the 
castings,  which  contain  and  give  oiF  heat  in  the  same  ratio  as  their  thickness.  As  a 
rule,  the  drag  or  bottom  side  of  a  casting  cools  first,  especially  if  a  mould  rests  on  the 
ground,  and  there  is  not  much  sand  between  the  casting  and  the  earth  ;  this  is  a  common 
-cause  of  unequal  cooling,  especially  in  large  flat  pieces.  Air  being  a  bad  conductor  of 
heat,  and  the  sand  usually  thin  on  the  cope  or  top  side,  the  result  is  that  the  top  of 
mould  remains  quite  hot,  while  at  the  bottom  the  earth,  being  a  good  conductor,  carries 
of  the  heat  and  cools  that  side  first,  so  that  the  iron  "sets  "  first  on  the  bottom,  after- 
■wards  cooling  and  contracting  on  the  top. 

The  draught,  or  the  taper  required  to  allow  patterns  to  be  drawn  readily,  is  another 
indefinite  condition  in  pattern-making :  may  be  -J„  in.  to  each  foot  of  depth,  or  1  in.,  or 
ihere  may  bo  no  draught  whatever.  Patterns  that  are  deep,  and  for  costings  that 
require  to  be  parallel  or  square  when  finished,  are  made  with  the  least  possible  amount 
of  draught ;  a  pattern  in  a  plain  form,  that  aflbrds  facilities  for  lifting  or  drawing,  may 
be  drawn  without  taper  if  its  sides  are  smooth  and  well  finished;  pieces  that  are  shallow 
and  moulded  often  should,  as  a  matter  of  convenience,  have  as  much  tnper  as  possible ; 
and  as  the  quantity  of  draught  can  be  as  the  depth  of  a  pattern,  we  frequently  see  them 
made  with  a  taper  that  exceeds  1  in.  to  the  foot  of  depth. 

Tools. — Tliese  include  crucibles  or  furnaces  for  melting  the  metal ;  pots  for  carrying 
it  to  the  moulds ;  moulding  flasks  and  implements  for  packing  them ;  clamps  for  holding 
the  moulds. 

Crucibles  vary  in  size,  shape,  and  composition,  according  to  their  destined  uses.  The 
so-called  "  plumbago"  crucibles,  made  of  graphite,  are  dearest  but  most  durable.  The 
cheaper  kinds  are  made  of  pipeclay.  They  are  charged  with  the  metal  to  be  melted,  and 
placed  in  a  sufficiently  strong  fire,  such  as  that  obtainable  on  a  smith's  forge.  For  con- 
siderable quantities  of  metal,  the  crucible  is  dispensed  with,  and  the  melting  is  conducted 
in  a  blast  furnace. 


38 


Casting  and  Founding — Iron. 


The  ironfonnJers'  pot  is  illustrated  in  Fig.  G,  and  consists  of  an  iron  pot  supported 
by  a  handle  which  is  single  at  one  end  and  double  at  the  other.  In  very  small 
operations  this  may  be  replaced  by  an  iron  ladle. 

Very  small  articles  can  bo  cast  in  moulds  made  of  stone,  brick,  or  iron,  the  interior 
surfaces  being  first  coated  with  a  "  facing"  of  soot,  by  holding  over  a  smoky  flame,  to 
prevent  adhesion  of  the  metal  -svheu  poured  in.     But  for  general  casting  operations, 
recourse  is  had  to  sand  packed 
into  "  flasks  "  or  "  boxes  "  sur- 
rounding the  pattern.    The  flask 
resembles  a  box,  without  top  or 
bottom,  and  made  in  2  sections,     g  ~ 

so  that  the  top  half  may  be  lifted 
away  from  tlie  bottom  half,  or 
joined  to  it  by  bolts  to  form  the 

whole.  Fig.  7  illustrates  the  upper  "  side  "  of  a  flask,  in  which  a  is  a  handle,  h  are  the 
holes  by  which  the  metal  is  poured  in,  and  c  are  lugs  carrying  pins  which  pass  through 
corresponding  holes  in  similar  lugs  on  the  bottom  side.  The  pattern  being  jjlaced  in  a 
flask  of  suitable  size,  the  space  intervening  on  all  sides  between  the  pattern  and  the 


1. 


flask  is  packe<l  in  with  sand,  which,  to  be  of  suitable  quality,  must  retain  a  ball  shape 
on  being  squeezed  in  Ihe  hand,  and  exhibit  an  impression  of  the  lines  and  inequalities 
of  the  skin  surface  that  pressed  it.  The  finest  quality  of  sand  is  placed  next  the  pattern, 
and  the  surface  of  tlie  latter  is  dusted  with  dry  "parting  sand,"  to  prevent  adhesion. 
The  packing  of  the  sand  is  performed  by  the  aid  of  a  moulding-trowel  (Fig.  8),  which 


9. 


consists  of  a  thin  steel  blade  in  a  wooden  handle  ;  a  moulding-wire  (Fig.  9),  useful  or 
smoothing  corners  and  removing  dirt  from  the  mould ;  and  a  stamper  (Fig.  10),  or 
pestle  of  hard  wood  or  iron.  Runner  sticks  of  smooth  tapering  form  are  inserted  in  the 
holes  b  of  the  flask,  to  make  feeding  ways  for  the  metal.     When  the  impress  of  the 


Casting  and  Founding — Iron.  39 

pattern  has  bccu  properly  taken  in  the  mould,  tbo  pattern  ia  removed,  and  the  top  and 
bottom  sides  of  the  flask  are  joined,  enclosed  on  tbo  open  sides  by  thick  boards,  and 
transferred  to  a  clamp  (2  boards  joined  by  adjustable  screws)  to  prevent  its  giving  way 
under  the  sudden  and  considerable  pressure  produced  by  the  weight  of  metal  poured  in, 
and  expansive  tendency  of  the  gases  generated. 

Casting  in  Sand. — The  foregoing  preparations  having  liecn  comiiletcd,  the  metal  may 
be  poured  in.  But  first,  to  prevent  the  metal  being  chilled  by  contact  with  the  saud, 
the  inside  of  the  mould  is  painted  over  with  a  blacking  made  of  charred  oak,  which 
evolves  gases  under  the  action  of  the  hot  iron,  and  prevents  too  close  a  contact  between 
the  metal  and  sand.  The  sand  is  also  pierced  with  holes  to  allow  of  the  escape  of  the 
air,  and  of  gases  evolved  when  the  metal  is  poured  in.  If  these  arc  allowed  to  force 
their  way  through  the  metal,  they  will  cause  it  to  be  unsoimd  and  full  of  flaws.  The 
passages  through  which  the  molten  iron  is  poured  into  the  mould  should  bo  so  arranged 
that  the  metal  runs  together  from  different  parts  at  the  same  time.  If  one  portion  get.s 
partially  cool  before  the  adjacent  metal  flows  against  it,  there  will  be  a  clear  division 
when  they  meet ;  the  iron  will  not  bo  run  into  one  mass,  but  will  form  what  is  called 
a  cold  shut.  The  above  is  the  simplest  form  of  the  process.  When  a  casting  is  to  Lo 
hollow,  a  pattern  of  its  inner  surface,  called  a  "core,"  is  formed  in  sand,  or  other  material, 
so  that  the  metal  may  flow  round  it.  This  leads  to  arrangements  in  the  pattern  whicli 
are  somewhat  complicated.  The  core  for  a  pipe  consists  of  a  hollow  metal  tube,  having 
its  surface  full  of  holes.  This  is  wound  round  with  straw  bands,  and  the  whole  is 
covered  with  loam  turned  and  smoothed  to  the  form  of  the  inside  of  the  pipe.  The 
strength  of  a  casting  is  increased  if  it  be  run  with  a  "  head  "  or  superincumbent  column 
of  metal,  which  by  its  weight  compresses  the  metal  below,  making  it  more  compact, 
and  free  from  bubbles,  scoria,  &c.  These  rise  into  the  head,  which  is  afterwards  cut 
off.  For  the  same  reason,  pipes  and  columns  are  generally  cast  vertically,  that  is  when 
the  mould  is  standing  on  end.  Tliis  position  has  another  advantage,  which  ia  that  the 
metal  ia  more  likely  to  be  of  uniform  density  and  thickness  all  round  than  if  the  pipe 
or  column  is  run  in  a  horizontal  position.  In  the  latter  case,  the  core  ia  very  apt  to  bo 
a  little  out  of  the  centre,  so  as  to  cause  the  tube  to  be  of  unequal  thickness.  In  casting 
a  large  number  of  pipes  of  the  same  size,  iron  patterns  are  used,  as  they  are  mo:e 
durable  than  wooden  ones,  and  draw  cleaner  from  the  sand.  Socket  pipes  should  bo 
cast  with  their  sockets  downwards,  the  spigot  end  being  made  longer  than  required  for 
the  finished  pipe,  so  that  the  scorioe,  bubbles,  &c.,  rising  into  it  may  be  cut  off.  Pipes 
of  very  small  diameters  are  generally  cast  in  an  inclined  position. 

Casting  in  Loam. — Large  pipes  and  cylinders  are  cast  in  a  somewhat  different  way. 
A  hollow  vertical  core  of  somewhat  less  diameter  than  the  interior  of  the  proposed 
cylinder  is  formed  either  in  metal  or  brickwork.  The  outer  surface  of  this  is  plastered 
with  a  thick  coating  of  loam  (which  we  may  call  A),  smoothed  and  scraped  to  the  exact 
internal  diameter  of  the  cylinder  (by  means  of  a  rotating  vertical  template  of  wood),  and 
covered  with  "  parting  mixture."  Over  this  is  spread  a  layer  of  loam  (B)  thicker  than 
the  proposed  casting ;  the  outer  surface  of  B  is  struck  with  the  template  to  the  form  of 
the  exterior  of  the  proposed  casting,  and  dusted  with  parting  mixture.  This  surface  is 
covered  with  a  third  thick  covering  of  loam  (C),  backed  up  with  brickwork,  forming  a 
"cope"  built  upon  a  ring  resting  on  the  floor,  so  that  it  can  be  removed.  The  outer 
brick  cope  is  then  temporarily  lifted  away  upon  the  ring.  The  coating  (B)  is  cleared 
out,  and  the  cope  is  replaced  so  that  the  distance  between  its  inner  surface  and  the  outer 
surface  of  A  is  equal  to  the  thickness  of  the  casting.  Tlie  metal  is  then  run  in  between 
C  and  A.  "When  cool,  C  and  A  can  be  broken  up,  and  the  casting  extracted.  The  core, 
&c.,  have  to  be  well  dried  in  ovens  before  the  metal  is  run.  B  is  often  dispensed  with, 
and  the  inner  surface  of  C  struck  with  the  template. 

Form  of  Castings. — The  shape  given  to  castings  should  be  very  carefully  considered. 
All  changes  of  form  should  be  gradual.   Sharp  corners  or  angles  are  a  source  of  weakness 


40  Casting  and  Founding— Iron. 

This  is  attributed  to  the  manner  in  which  the  crystals  composing  the  iron  arrange 
themselves  in  cooling.  They  place  themselves  at  right  angles  to  the  surfaces  forming 
tlie  corner,  so  that  between  the  two  sets  of  crystals  tliere  is  a  diagonal  line  of  weakness. 
All  angles,  therefore,  both  external  and  internal,  should  be  rounded  off.  There  should 
be  no  great  or  abrupt  differences  in  the  bulk  of  the  adjacent  parts  of  the  same  casting, 
or  the  smaller  portions  will  cool  and  contract  more  quickly  than  the  larger  parts.  When 
the  different  parts  of  the  casting  cool  at  different  times,  each  acts  ui^on  the  other.  The 
parts  which  cool  first  resist  the  contraction  of  the  others,  while  those  which  contract  last 
compress  the  portions  already  cool.  Thus  the  casting  is  under  stress  before  it  is  called 
upon  to  bear  any  load.  The  amount  of  this  stress  cannot  be  calculated,  and  it  is  there- 
fore a  source  of  danger  in  using  the  casting.  In  some  cases  it  is  so  great  as  to  fracture 
the  casting  before  it  is  loaded  at  all.  Tlie  internal  stress,  produced  by  unequal  cooling 
in  the  difterent  parts  of  a  casting,  sometimes  causes  it  to  break  up  spontaneously  several 
days  after  it  has  been  run.  Castings  should  be  covered  up  and  allowed  to  cool  as  slowly 
as  possible;  they  should  remain  in  the  sand  until  cool.  If  they  are  removed  from  the 
mould  in  a  red-hot  state,  the  metal  is  liable  to  injury  from  too  rapid  and  irregular 
cooling.  The  unequal  cooling  and  consequent  injury,  caused  by  great  and  sudden 
differences  in  the  thickness  of  parts  of  a  casting,  are  sometimes  avoided  by  uncovering 
the  thick  parts  so  that  they  may  cool  more  quickly,  or  by  cooling  them  with  water.  It 
is  generally  thought  that  molten  cast-iron  expands  slightly  just  at  the  moment  when  it 
becomes  solid,  which  causes  it  to  force  itself  tightly  into  all  the  corners  of  the  mould, 
and  take  a  sharp  impression.  This,  however,  has  been  disputed.  Superior  castings 
shouhl  never  be  run  direct  from  the  furnace.  The  iron  should  be  remelted  in  a  cupola. 
This  is  called  "  second  melting ; "  it  greatly  improves  the  iron,  and  gives  an  opportunity 
for  mixing  different  descriptions  which  improve  one  another.  Castings  required  to  be 
turned  or  bored,  and  found  to  be  too  hard,  are  softened  by  being  heated  for  several  hours 
in  sand,  or  in  a  mixture  of  coal-dust  and  bone-ash,  and  then  allowed  to  cool  glowly. 

Examination  of  Casings. — In  examining  castings,  with  a  view  to  ascertaining  their 
quality  and  soundness,  several  points  should  be  attended  to.  The  edges  should  be  struck 
witli  a  light  hammer.  If  the  blow  make  a  slight  impression,  the  iron  is  probably  of 
good  quality,  provided  it  be  uniform  throughout.  If  fragments  Hy  off  and  no  sensible 
indentation  bo  made,  the  iron  is  hard  and  brittle.  Air  bubbles  are  a  common  and 
dangerous  source  of  weakness.  They  should  be  searched  for  by  tapping  the  surface  of 
the  casting  all  over  with  the  hammer.  Bubbles,  or  flaws,  filled  in  with  sand  from  the 
mould,  or  pm-posely  stopijed  with  loam,  cause  a  dulness  in  the  sound  which  leads  to 
their  detection.  The  metal  of  a  casting  should  be  free  from  scoriaj,  bubbles,  core  nails, 
or  flaws  of  any  kind.  The  exterior  surface  should  be  smooth  and  clear.  The  edges  of 
the  casting  should  be  sharp  and  perfect.  An  uneven  or  wavy  surRice  indicates  unequal 
shrinkage,  caused  by  want  of  uniformity  in  the  texture  of  the  iron.  The  surface  of  a 
fracture  examined  before  it  has  become  rusty  should  present  a  fine-grained  texture,  of  an 
uniform  bluish-grey  colour  and  high  metallic  lustre.  Cast-iron  pipes  sliould  be  straight, 
true  in  section,  square  on  the  ends  and  in  the  sockets,  the  metal  of  equal  thickness 
throughout.  They  should  be  proved  under  a  hydraulic  pressure  of  4  or  5  times  the 
working  head.  The  sockets  of  small  pipes  should  be  especially  examined,  to  see  if  they 
are  free  from  honeycomb.  The  core  nails  are  sometimes  left  in  and  hammered  up. 
They  are,  however,  objectionable,  as  they  render  the  pipe  liable  to  break  at  the  points 
where  tliey  occur. 

As  there  ia  an  endless  variety  of  patterns  from  which  moulds  arc  made,  it  will  be 
necessary  to  divide  them  into  light  and  lieavy  work.  Stove  castings  are  very  light.  In 
tlie  moulding  of  such  work,  much  depends  upon  the  quality  of  sand  used ;  the  moulders' 
lieap  should  be  Composed  of  no  more  than  ^  loam,  the  other  i  bein"-  a  very  open  sand. 
This  makes  a  good  strong  mixture,  which  will  not  allow  the  sharp  corners  and  fine 
ornamental  work  to  be  washed  away  when  the  molten  iron  is  poured  into  the  mould,     la 


Casting  and  Founding — Iron.  41 

ramming  such  work,  the  moulder  should  be  careful  that  the  sand  on  top  and  bottom  of 
lais  pattern  is  not  rammed  hard  ;  but  the  sides  or  edges  should  be  well  rammed,  in  onier 
that  the  casting  may  not  strain  from  having  a  soft  parting.  Great  care  should  be  taken 
to  see  that  the  bottom  board  is  well  bedded  on  the  flask,  after  which  it  should  be 
removed  and  the  vent  wire  used  freely.  The  venting  of  the  work  is  often  but  partially 
done,  on  account  of  the  point  of  the  vent  wire  coming  into  contact  with  the  pattern  ;  and 
when  the  iron  enters  the  mould,  it  finds  its  way  into  said  vents,  fills  them  up,  and  thus, 
in  a  measure,  prevents  the  escape  of  the  gas  that  arises  from  the  iron  coming  in  contact 
with  the  charcoal,  graphite,  or  soapstone  with  which  the  mould  has  been  dusted  to  pre- 
vent the  sand  from  adhering  to  the  casting.  The  bottom  board  should  then  be  carefully 
replaced  on  the  flask,  and  dogged  down  so  that  in  the  act  of  turning  it  over  it  cannot 
move,  which  would  cover  the  vents  over  with  sand.  The  top  part  of  the  flask  (or  cope, 
as  it  is  termed)  needs  the  same  care  in  ramming  over  the  pattern  as  the  bottom,  and 
should  be  well  vented.  If  the  mould  has  any  high  projections  in  the  cope,  they  should 
be  well  vented ;  for  it  is  at  these  elevated  points  that  a  large  portion  of  the  gas  accumu- 
lates and  needs  a  quick  exit,  in  order  to  make  sharp  corners  on  the  casting  and  prevent 
blowing.  The  strainings  of  castings  in  this  branch  of  the  trade  is  greatly  due  to  an 
insufiicicnt  amount  of  weight  being  placed  on  the  flask,  or  the  parts  not  being  properly 
dogged  together,  as  well  as  to  the  rapidity  with  which  the  iron  is  poured  into  the  mould, 
together  with  the  height  of  the  runner.  Cutting  short  the  supply  of  iron  as  soon  as  the 
runner  is  full,  and  a  careful  watching  of  the  work  to  be  poured,  will  in  most  cases 
remedy  the  trouble  of  the  casting  being  tliickcr  than  the  pattern. 

As  to  the  warping  of  the  plates,  much  dejjends  upon  the  quality  of  iron  used  and  the 
judgment  of  the  pattern-maker.  It  can  often  be  prevented,  in  a  measure,  by  the  moulder, 
in  making  the  runner  from  the  round  sprue  no  thicker  than  the  piece  to  be  cast ;  and  as 
soon  as  the  metal  is  poured,  by  digging  away  in  front  of  the  sprue  and  breaking  it  loose 
from  the  casting.  Where  a  flat  sprue  is  used,  tliis  breaking  off"  should  invariably  be  done 
as  soon  as  the  runner  is  cool  enough.  Being  wedge-shaped,  with  the  small  end  of  the 
wedge  downwards,  it  lifts  a  portion  of  the  casting  in  shrinking,  and  thus  causes  it  to  be 
out  of  shape. 

In  heavy  work,  care  and  judgment  are  needed,  and  it  requires  a  man's  lifetime  to 
become  proficient.  In  ramming  work  that  is  to  bo  poured  on  its  end,  having  a  height  of 
3  or  4  ft.,  there  is  no  risk  in  well  packing  the  sand,  for  f  its  height,  around  the  pattern  ; 
and  as  you  near  the  top,  ram  it  as  you  would  a  pattern  no  more  than  1  ft.  in  thickness. 
The  sand  in  all  such  work  should  be  very  open  or  porous,  in  order  to  prevent  scabbing. 
As  there  is  so  large  a  quantity  of  iron  used,  much  steam  and  gas  are  generated  in  the 
mould ;  and  as  there  is  no  other  way  of  escape  for  them  but  through  the  vents,  there 
should  be  no  fault  in  this  particular  part  of  the  mould.  In  the  pouring  of  such  work,  it 
is  best  to  run  it  from  the  bottom.  If  a  runner  is  used,  do  not  raise  the  risers  to  correspond 
in  height  with  the  runner,  as  by  so  doing  you  increase  the  amount  of  strain  on  the  mould  ; 
but  form  a  little  basin  around  the  risers  by  ramming  out  the  sprue  holes  with  the  finger, 
juid  on  the  side  nearest  the  outer  edge  of  the  flask  form  a  lip  for  the  surplus  ii'on  in  the 
runner  to  run  over  on  to  the  floor.  When  heavy  work  is  bedded  in  the  floor,  too  much 
care  cannot  be  taken  in  preventing  the  dampness  of  the  ground  beneath  from  striking 
through  into  the  mould.  The  sand  that  is  thrown  out  of  the  pit,  if  it  has  been  of  long 
standing,  should  not  be  used  for  the  moulding  of  that  piece  ;  for  it  is  too  cold  and  damp 
and  sliould  be  thrown  on  one  side,  and  allowed  to  stand,  that  it  may  dry  and  warm  up. 
The  2  or  3  ladlefuls  of  iron  that  remain  in  tiie  furnace  after  tlie  work  on  the  floor  has 
been  poured,  can  be  run  into  pigs  in  tliis  sand,  which  will  greatly  help  to  fit  it  for 
immediate  use.  In  the  venting  of  heavy  work,  the  small  vents  should  terminate  iu  a 
number  of  large  ones,  which  should  have  an  opening  on  both  sides  of  the  mould  : 
then  a  draught  would  be  formed  to  carry  off  the  gas  which  is  continually  growing  as  tho 
workman  is  in  the  act  of  pouring  the  iron  into  the  mould. 


42 


Casting  and  Founding — Iron. 


All  men  connected  with  this  branch  of  the  trade  have  heard  that  sharjj  report  which 
immediately  follows  the  pouring  of  a  large  piece,  and  which  is  caused  by  the  confined 
gas  in  the  lower  end  of  a  large  vent,  there  being  no  draught  to  drive  it  oat.  Where 
facing  is  used,  much  more  care  is  needed  in  venting.  In  the  making  of  large  pulleys 
and  gear-wheels,  too  much  care  cannot  be  taken  in  this  particular.  Not  so  much 
depends  uj^on  the  ramming  of  such  work  as  upon  the  venting  for  the  proper  exit  of  the 
gas  from  the  sand  in  the  immediate  vicinity  of  the  mould  ;  for  if  the  mould  has  been 
rammed  harder  than  there  was  any  necessity  fur,  and  the  venting  has  been  properly 
looked  after,  there  is  not  much  danger  of  the  casting  being  a  poor  one.  Such  work 
should  invariably  be  run  from  the  hub  or  centre,  with  sufiicient  risers,  arranged  as 
above  described.  This  branch  of  the  trade  is  called  green-sand  work,  and  it  involves  a 
large  part  of  the  art  of  ramming. 

Shrinlcage  of  Iron  Castings. — The  chief  trouble  with  iron  castings  is  their  liability  to 
have  internal  strains  put  upon  them  in  cooling,  in  consequence  of  their  shrinking.  The 
amount  of  this  shrinkage  varies  with  the  quality  of  the  metal,  and  with  the  size  of  the 
casting  and  its  comparative  thickness.  Thus  locomotive  cylinders  shrink  only  about 
-jL  in.  per  ft.  (1-192  =  -0052),  while  heavy  pipe  castings  and  girders  shrink  -j^j  in.  per 
ft.  (1-120  =  -0083),  or  even  i  in.  per  ft.  (1-06  =  -0101).  While  small  wheels  shrink 
only  Jg-  in.  per  ft.  (1-300  —  -0033),  large  and  heavy  ones  contract  Jjj  in.  per  ft. 
(1-120  =  '0083).  The  "  shrink-rule  "  is  emijloyed  by  pattern-makers  to  relieve  them 
of  the  labour  of  calculating  these  excesses,  the  scales  being  graduated  to  inches,  &c., 
which  are  "  0052,  •  0083,  &c.,  too  long.  Now,  if  thick  metal  proportionately  shrinks 
more  than  thin,  we  must  expect  any  casting  not  absolutely  symmetrical  in  every  direc- 
tion to  change  its  form  or  proportion.  A  cubic  or  spheric  mould  yields  a  cube  or  a 
sphere  as  a  casting;  but  a  mould,  say  of  the  proportions  of  100  X  5  x  1,  shrinking 
differently  according  to  dimensions,  gives  a  casting  not  only  less  in  size  but  in  somewhat 
different  proportion.  In  many  cases  we  still  find  them  strained  and  twisted.  Those 
parts  which  cool  first  get  their  final  proportions,  and  the  later  cooling  portions  strain  the 
earlier,  the  resistance  of  which  to  defor- 
mation puts  strains  on  those  cooling. 
This  initial  strain  may  of  itself  break 
the  casting,  and,  if  not,  will  weaken  it. 
Castings  of  excessive  or  varying  thick- 
ness, and  of  complicated  form,  are  most 
in  danger  from  internal  strain.  This 
strain  is  gradually  lessened  in  time  by 
the  molecules  "  giving."  In  a  casting 
Buch  as  a  (Fig.  11),  say  a  thick  press 
cylinder,  the  outer  layers  solidify  and 
shrink  first,  and  as  the  inner  laj'crs 
contract  after  the  outer  ones  have  "  set,'' 
there  is  compression  of  the  outer  layers 
and  tension  of  the  inner.  Such  a 
cylinder  will,  if  subjected  to  internal 
pressure,  be  weak,  because  there  is 
already  in  the  inner  layers  a  force 
tending  to  csi^and  them.  The  cylinder 
would  bo  stronger  if  these  layers  were  braced  to  resist  extension,  or,  in  other  words, 
were  already  in  compression.  If  we  cool  the  interior  first,  by  artificial  means,  while 
delaying  tJie  cooling  of  the  exterior  layers,  we  have  these  layers  braced  to  receive 
gradual  or  sudden  pressure,  and  this  is  especially  desirable  in  cannon.  In  a  panel 
like  b,  with  a  thin  but  rigid  flange,  the  diagonals  slirink  more  slowly  than  the  rim, 
and  a  crack  is  likely  to  appear.     A  casting  like  that  ia  c  would  solidify  on  the  thin 


Casting  and  Founding — Iron.  43 

side  first,  and  when  the  thick  side  shrank,  it  wonld  curve  the  bar  and  compress  the 
thick  part,  and  put  the  thiu  in  tension.  Wheel  and  pulley  castings  d  are  especially 
troublesome.  The  latter  have  a  thin  rigid  rim,  which  cools  before  •the  arms,  and  when 
the  latter  cool  they  are  very  apt  to  break  by  tension.  If  the  arms  set  jirst,  tliey  aro 
apt  to  break  the  rim,  as  they  make  a  rigid  abutment  which  resists  the  rim-contraction, 
bending  the  rim  and  breaking  it  from  within  outwards.  In  the  cooling  of  casting!--, 
the  particles  range  themselves  in  crystals  perpendicular  to  the  cooling  surface ;  hence 
we  may  expect  to  find  weak  points  at  sharp  corners,  as  in  e.  The  remedy  for  this  is  to 
round  off  all  angles. 

Chilling  Iron  Castings. — The  service  part  of  a  casting  that  is  wanted  to  retain  a 
certain  shape,*  size,  and  smoothness,  and  to  withstand  constant  wear  and  tear,  can  in 
most  cases  be  chilled,  when  cast,  by  forming  the  shape  of  iron  instead  of  sand.  The 
iron  mould  or  chill,  when  made  of  cast-iron,  should  bo  of  the  best  strong  iron,  having 
very  little  contraction,  as  the  sudden  heating  of  the  surfaces  by  the  melted  iron  is  liable 
to  crack  it,  so  that  in  a  short  time  the  face  will  be  full  of  small  cracks  or  raised  blisters. 
When  melted  grey  iron  is  poured  around  or  against  the  surface  of  solid  iron,  it  is  chilled 
i  in.  to  1  in.  in  depth,  depending  on  the  hardness  and  closeness  of  the  iron  the  mould  is 
poured  with.  In  order  to  chill  this  u-on  as  deep  as  1 J  in.  and  upward,  tliere  must  be 
some  cast  steel  melted  in  the  cupola.  The  proportion  will  depend  on  the  quality  of 
the  iron  and  steel  used.  Steel  borings  can  be  put  into  the  ladles,  and  the  hot  iron  let 
mix  with  them  ;  but  "the  best  plan  is  to  have  some  old  steel  castings  or  pieces  of 
steel  rails,  and  melt  them  in  the  cupola,  and  when  the  ii-on  is  in  the  ladle,  mix  or 
stir  the  metal  with  a  large  rod.  AVith  strong,  close  iron,  about  1  part  steel  to  5  of 
iron  will  cause  a  chill  of  H  in.  Iron  for  making  chilled  castings  should  be  strong, 
as  chilling  iron  impairs  its  strength.  An  iron  that  contracts  very  little  in  cooling  is 
of  the  greatest  importance  in  keeping  chilled  castings  from  checking  or  cracking. 
The  following  may  explain  the  cause  of  chilled  casting  being  bad. 
Melted  iron,  when  poured  inside  a  chill,  similar  to  a  roll  or  car-wheel  chill,  cools 
and  forms  a  shell  in  a  very  short  time,  the  thickness  of  which  will  depend  on  the  hardness 
and  temperature  of  the  iron.  It  is  during  tlie  course  of  the  first  2  or  3  minutes  that 
the  checking  or  cracking  takes  place;  for  as  soon  as  melted  iron  commences  to  cool 
or  freeze,  it  starts  to  contract  more  or  less,  and  as  the  shell  thus  formed  becomes  cool,  or 
half-molten,  it  contracts  and  leaves  the  surface  of  the  chill,  so  that  the  contracting  shell 
stands,  or  holds  in  the  pressure  of  the  liquid  iron  inside.  Should  the  mould  not  be 
dead  level,  the  inside  liquid  metal  will  have  the  most  pressure  at  the  lowest  point  of  the 
shell,  and  will  cause  this  part  to  burst  open.  A  check  or  crack  never  starts  at  the  top 
part  of  a  mould,  but  always  at  the  bottom,  and  if  you  look  closely  at  one  of  these  cracks 
you  will  see  it  is  the  largest  at  the  bottom,  and  running  up  to  nothing.  In  some  cases 
you  can  see  where  the  inside  liquid  iron  has  flowed  out,  and  partly  filled  up  the  crack. 

So  far  as  mixing  the  iron  is  concerned,  it  will  stand  a  deal  of  variation,  and  it  is 
a  poor  excuse  for  a  moulder  to  put  the  blame  on  the  melter  for  3  or  4  bad  wheels  out 
of  a  heat  of  16,  If  he  would  make  a  straight  edge  that  would  reach  across  the  top 
and  come  down  on  to  the  turned  level  face  of  the  chill,  and  then  level  his  flasks  instead 
of  dumping  them  in  any  shape,  the  melter  would  not  get  blamed  so  much  as  he  does 
for  cracked  wheels. 

In  making  chilled  rolls,  the  temperature  of  the  iron  is  as  important  a  point  as  it  is  in  the 
manufacture  of  car-wheels.  The  iron  should  be  poured  as  dull  as  possible,  for  the  duller 
the  iron  the  quicker  and  thicker  is  the  outside  shell  formed,  thereby  offering  a  stronger 
j  resistance  to  the  pressure  of  the  inside  liquid  iron.  Of  course,  the  moulder  must  use 
j  his  judgment  in  cooling  off  the  iron,  for  if  too  dull,  the  face  of  the  chilled  part  will 
I  be  cold  shut,  and  look  dirty.  The  rolls  should  be  poured  quickly  at  the  neck,  and  the 
1  gates  cut,  so  as  to  whirl  the  iron  and  keep  all  dirt  in  the  centre  and  away  from  the 
I  face  of  the   chill.     When  the  mould  is  full,  do  not  put  in  the  feeding-rod  until  tlie 


44  Casting  and  Founding — Iron. 

neck  13  about  to  freeze  up.  When  you  do  put  it  in,  do  not  ram  it  down  suddenly 
so  as  to  cause  a  pressure  on  the  contracting  shell,  wliich  would  be  liable  to  crack  it. 
When  feeding,  work  the  rod  slowly.  It  is  better  to  make  the  chills  as  hot  as  possible 
by  heating  them  in  the  oven,  as  the  iron  will  lie  closer  and  make  a  smoother  casting 
against  a  hot  chill  than  when  poured  against  a  cold  one.  By  having  the  mould  dead 
level,  the  pressure  will  be  equal  all  around.  Whenever  there  is  a  check  or  crack,  you 
may  depend  that  it  is  caused  by  unequal  pressure  of  the  confined  liquid  metal  against 
the  contracting  shell. 

FORGING  AND  FINISHING.— These  terms  are  defined  by  Eichards,  in 
his  '  Workshop  Manipulation,'  in  the  following  words :  "  Forging  relates  to  shaping 
metal  by  compression  or  blows  when  it  is  in  a  heated  or  softened  condition ;  as  a 
process  it  is  an  intermediate  one  between  casting  and  what  may  be  called  the  cold 
processes.  Forging  also  relates  to  welding  or  joining  pieces  together  by  sudden 
heating  that  melts  the  surface  only,  and  then  by  forcing  the  pieces  together  while  in 
this  softened  or  semi-fused  state.  Forging  includes,  in  ordinary  practice,  the  preparation 
of  cutting  tools,  and  tempering  them  to  various  degrees  of  hardness  as  the  nature  of 
the  work  for  which  they  are  intended  may  require ;  also  the  construction  of  furnaces 
for  heating  tlie  material,  and  mechanical  devices  for  handling  it  when  hot,  with  the 
various  operations  for  shaping.  Finishing  and  fitting  relate  to  giving  true  and  accurate 
dimensions  to  the  parts  of  machinery  that  come  in  contact  with  each  other  and  are 
joined  together  or  move  upon  each  other,  and  consist  in  cutting  away  the  surplus  material 
■which  has  to  be  left  in  founding  and  forging  because  of  the  heated  and  expanded 
condition  in  which  the  material  is  treated  in  these  last  processes.  In  finishing,  material 
is  operated  upon  at  its  normal  temperature,  in  which  condition  it  can  be  handled, 
gauged,  or  measured,  and  will  retain  its  shape  after  it  is  fitted.  Finishing  compre- 
hends all  operations  of  cutting  and  abrading,  such  as  turning,  -boring,  planing,  and 
grinding,  also  the  handling  of  material ;  it  is  considered  the  leading  department  in 
shop  manipulation,  because  it  is  the  one  where  the  work  constructed  is  organized  and 
brought  together.  The  fitting  shop  is  also  that  department  to  which  drawings 
especially  apply,  and  other  preparatory  operations  are  usually  made  subservient  to  the 
fitting  processes.  A  peculiarity  of  forging  is  that  it  is  a  kind  of  hand  process,  where 
the  judgment  must  continually  direct  the  operations,  one  blow  determining  the  next, 
and  while  pieces  forged  may  be  duplicates,  there  is  a  lack  of  uniformity  in  the  manner 
■of  producing  them.  Pieces  may  be  shaped  at  a  white  welding  heat  or  at  a  low  red 
heat,  by  one  or  two  strong  blows  or  by  a  dozen  lighter  blows,  the  whole  being  governed 
by  the  circumstances  of  the  work  as  it  progresses.  A  smith  mny  not  throughout  a 
whole  day  repeat  an  operation  precisely  iu  the  same  manner,  nor  can  he,  at  the  beginning 
of  an  operation,  tell  the  length  of  time  required  to  execute  it,  nor  even  the  precise 
manner  in  which  he  will  perform  it.  Such  conditions  are  peculiar,  and  apply  to  forging 
alone." 

The  technical  phrases  employed  in  forging  are  thus  explained  by  Cameron 
Knight : — 

To  "  make  up  a  stock."— The  "  stock "  is  that  mass  of  coal  or  coke  which  is 
situated  between  the  fire  and  the  cast-iron  plate,  through  the  opening  in  which  the 
wind  or  blast  is  forced.  The  size  and  shape  of  this  stock  depend  upon  the  dimensions 
and  shape  of  the  work  to  be  produced.  To  make  up  a  stock  is  to  place  the  coal  in 
proper  position  around  the  taper-ended  rod,  which  is  named  a  "  plug."  The  taper  end 
of  the  plug  is  push(-d  into  the  opening  from  which  comes  the  blast;  the  other  end  of 
the  plug  is  then  laid  across  the  hearth  or  fireplace,  after  which  the  wet  small  coal  is 
thoroughly  battered  over  the  plug  while  it  remains  in  the  opening,  and  the  coal  piled 
up  till  the  required  height  and  width  of  the  stock  is  reached  ;  after  which  the  plug  is 
taken  out  und  tlie  fire  made,  the  blast  in  the  meantime  freely  traversing  the  opening 
made  in  the  stock  by  the  plug. 


Forging  and  Finishing.  45 

Fire-irons. — These  consist  of  a  poker  with  small  hook  at  one  end,  a  slice,  and  rake. 
The  poker  with  small  h(jok  is  used  for  clearinpc  away  the  clinker  from  the  blast-hole, 
also  for  holding  small  pieces  of  work  in  the  fire.  The  slice  is  a  small  Hat  shovel  or 
spade,  and  is  used  for  battering  the  coal  while  making  up  a  stock.  The  slice  is  also 
used  for  adding  coal  to  the  fire  when  only  a  small  quantity  is  required  at  one  time. 
The  rake  consists  of  a  rod  of  iron  or  steel  with  a  handle  at  one  end,  and  at  the  other  a 
right-angle  bend  of  flat  iron,  and  is  used  to  adjust  the  coal  or  coke  into  proper  position 
while  the  piece  to  bo  forged  is  in  the  fire. 

Eod. — This  term  is  usually  applied  to  a  long  slender  piece  of  iron,  wdiose  section 
is  circular. 

Bar. — Bar  signifies  a  rod  or  length  of  iron  whose  section  is  square,  or  otherwise 
angular,  instead  of  circular. 

Plate. —  This  term  is  applied  to  any  piece  of  iron  whose  length  and  breadth  vciy 
much  exceed  its  thickness.     Thin  plates  of  iron  are  termed  '•  sheets." 

To  "  take  a  heat." — This  signifies  to  allow  the  iron  to  remain  in  the  fire  until  the 
required  heat  is  obtained.  To  "  take  a  welding  heat "  is  to  allow  the  iron  to  remain  in 
the  fire  till  hot  enough  to  melt  or  partially  melt. 

To  "  finish  at  one  heat "  is  to  do  all  the  required  forging  to  the  piece  of  work  in  hand 
by  heating  once  only. 

To  "  draw  down." — Drawing  down  signifies  reducing  a  thick  bar  or  rod  of  iron  to  any 
required  diameter.  There  are  several  methods  of  drawing  down :  by  a  single  hammer 
in  the  hand  of  one  man ;  by  a  pair  of  hammers  in  the  hands  of  2  men  ;  5  or  G  hammers 
may  be  also  used  by  5  or  6  men.  Drawing  down  is  also  effected  by  steam-hammers, 
air-hammers,  and  rolling-mills. 

To  "  draw  away." — This  term  signifies  the  same  as  to  draw  down. 

To  "  upset." — This  operation  is  the  reverse  of  drawing  down,  and  consists  in  making 
a  thin  bar  or  rod  into  a  thick  one ;  or  it  may  consist  in  thickening  a  portion  only,  such 
as  the  middle  or  end,  or  both  ends.  The  operation  is  performed  by  heating  the  iron  to 
a  yellow  heat,  or  what  is  named  a  white  heat,  and  placing  one  end  upon  tiie  anvil,  or 
upon  the  ground,  and  striking  the  other  end  with  3  or  4  hammers,  as  required.  Iron 
may  be  also  upset,  while  in  the  horizontal  position,  by  pendulum  hammers  and  by 
the  steam-striker,  which  will  deliver  blows  at  any  angle  from  horizontal  to  vertical. 

Scarfing. — This  operation  includes  2  processes — upsetting  and  bevelling.  Scarfing 
is  resorted  to  for  the  purpose  of  properly  welding  or  joining  2  pieces  of  iron  together. 
When  the  pieces  are  rods  or  bars,  it  is  necessary  to  upset  the  2  ends  to  be  welded,  so 
that  tlie  hammering  which  unites  the  pieces  shall  not  reduce  the  iron  below  the 
required  dimensions.  After  being  upset,  the  2  ends  are  bevelled  by  a  fuller  or  by 
the  hammer. 

Butt-weld. — When  a  red  or  bar  is  welded  to  another  bar  or  plate,  so  tiiat  the  joint 
shall  be  at  right  angles  to  the  bar,  it  is  termed  a  butt-weld. 

Tongue-joint.— This  joint  is  made  by  cutting  open  the  end  of  a  bar  to  be  welded 
to  another,  whose  end  is  tapered  to  fit  the  opening,  aud  then  welding  the  2  bars  together. 

To  "  punch"  is  to  make  a  hole,  either  square  or  round,  in  a  piece  of  iron  by  means 
of  square  or  round  taper  tools,  named  punches,  which  are  driven  through  the  iron  by 
hand-hammers  or  by  steam-hammers. 

To  "drift  out"  is  to  enlarge  a  hole  by  means  of  a  taper  round  or  square  tool, 
named  a  drift. 

The  hammerman  is  the  assistant  to  the  smith,  and  uses  the  heavy  hammer,  named 
the  sledge,  when  heavy  blows  are  required. 

The  Tuyere  or  Tweer. — This  is  a  pipe  through  which  the  blast  of  air  proceeds  to 
the  stock,  and  thence  to  the  fire.  The  nozzle  of  the  tweer  is  the  extreme  end  or 
portion  of  the  tweer  which  is  inserted  into  the  opening  of  the  plate  against  which  the 
etock  is  built.     C  Mechanician  and  Constructor.') 


46 


I'ORGING   AND   FINISHING. 


Forgi's  or  Eearths.— These  are  made  in  a  great  variety  of  form  and  size,  some 
obtaining  the  necessary  blast  by  means  of  bellows,  others  by  rotary  fans  or  blowers ; 
some  -with  a  single  and  others  with  a  double  blast ;  some  with,  others  without  hoods ; 
according  to  the  work  they  arc  destined  for.  Fig.  12  illustrates  a  "  Cyclops  "  circular 
forge,  with  a  pan  20  in.  across,  weighing  altogether  lOG  lb., 
and  costing  90s. ;  this  size  is  only  suited  for  riveting.  The 
blast  is  produced  by  a  small  rotary  blower.  The  square 
form  of  pan,  3i  in.  by  20  in.,  will  beat  2-in.  round  iron, 
weighs  2  cwt.,  and  costs  140s.  Fig.  13  is  a  portable  forge, 
the  pan  consisting  of  a  box  made  with  thin  iron  jdates, 
19  in.  square  and  9  in.  high  when  closed,  as  shown  at 
B,  and  capable  of  containing  all  the  tools  accompanying  the 
forge,  as  well  as  the  bellows  and  legs.  This  forge  is 
made  by  Schaller,  of  Vienna,  and  is  much  used  in  the 
Austrian  army.  In  large  forges  the  tuyere  pipe  feeding  the 
blast  to  the  fire  is  rendered  more  durable  by  the  constant 
application  of  a  stream  of  cold  water. 

jljivih. — An  anvil  is  an  iron  block,  usually  with  a  steel 
face,  upon  which  metal  is  hammered  and  shaped.     The 

ordinary  smith's  anvil,  Figs.  1-t  and  15,  is  one  solid  mass  of  metal, — iron  in  different 
states ;  C  is  the  core  or  body ;  B,  4  corners  for  enlarging  the  base ;  D,  Fig.  14,  the 
projecting  cud  ;  it  contains  one  or  two  holes  for  the  reception  of  set  chisels  in  cutting 


pieces  of  iron,  or  for  the  reception  of  a  shaper,  as  shown  at  E,  Fig.  15.  In  punching 
flat  pieces  of  metal,  in  forming  the  heads  of  nails  or  bolts,  and  in  numerous  other  cases, 
these  holes  «  of  ordinary  anvils  are  not  only  useful  but  indispensable.     The  beak- 


Forging  and  Finishing. 


47 


Lorn  A  16  used  for  turning  pieces  of  iron  into  a  circular  or  curved  form,  vreldin"- 
hoops,  and  for  other  similar  operations.  In  the  smithery,  the  anvil  is  generally 
seated  on  the  root  end  of  a  beech  or  oak  tree ;  the  anvil  and  wooden  block  must 
be  firmly  connected,  to  render  the  blows  of  the  hammer  effective;  and  if  the  block  bo 


15. 


not  firmly  connected  to  the  earth,  the  blows  of  the  hammer  will  not  tell.  The  best 
anvils,  anvil-stakes,  and  planishing  hammers  are  faced  with  double  shear-steel.  The 
steel-facings  are  shaped  and  laid  on  a  core  at  a  welding  heat,  and  the  anvil  is  completed  by 
being  reheated  and  hammered. 

When  the  steel-facuig  is  first  16. 

applied,  it  is  less  heated  than 
the  core.  But  the  proper 
hardening  of  the  face  of  the 
anvil  requires  great  skill ;  the 
face  must  be  raiised  to  a  full 
red-heat,  and  placed  under  a 
descending  column  of  water,  so 
that  the  surface  of  the  face  may 
continue  in  contact  with  the 
successive  sui^ply  of  the  quench- 
ing fluitl,  which  at  the  face 
retains  the  same  temperature, 
as  it  is  rapidly  sui^plied.     The 

rapidity  of  the  flow  of  water  may  be  increased  by  giving  a  sufficient  height  to  its 
descending  column ;  it  is  important  that  the  cooling  stream  should  fall  perpendicularly 
to  the  face  which  is  being  hardened.  Heat  may  escape  parallel  to  the  face,  but  not  in 
the  direction  of  the  falling  water. 
The  operator,  during  this  hardening 
process,  is  protected  from  spray  and 
smoke  by  a  suitable  cover,  and  by 
confining  the  falling  water  to  a  tube 
which  must  contain  the  required 
volume.  When  an  anvil  is  to  be 
used  for  planishing  metals,  it  is 
polished  with  emery  and  crocus 
ITOwders.  It  is  better  to  be  too 
heavy   than   too    light,    and    may 

range  from  2  to  5  cwt.,  according  to  the  work  to  be  done  on  it.  On  being  tapped  with 
a  hammer,  it  should  give  out  a  clear  ringing  note.  It  is  generally  used  with  the  tail 
(square)  end  towards  the  right  hand,  and  the  horn  (beak  iron)  towards  the  left. 

Vices  and  Tongs, — Of  vices  there  is  a  great  variety ;  Fig.  16  is  a  typical  example 


48 


Forging  and  Finishing. 


of  a  malleable  iron  jiarallel  vice.  Fig.  17  is  a  iiseful  little  combined  anvil  and  vice,  face 
10  in.  by  4,  4-in.  jaw,  weight  40  lb.,  costing  22s.  Gd.  Tongs  are  usually  home-made, 
and  will  be  described  further  on. 

ITammers.— Upon  the  principles  underlying  the  shapes,  sizes,  and  uses  of  hammers, 
much  will  be  found  under  the  heading  of  Carpentry.  A  few  representative  forms  of 
hammer  head  are  shown  in  Figs.  18, 19 :  a  to  d  are  used  by  engineers  and  mechauics, 

18 


c  to  k  by  boiler- makers,  while  I  is  a  sledgehammer.  All  but  I  are  hand-hammers.  They 
differ  mainly  in  the  form  of  the  pane,  the  head  remaining  pretty  much  the  same ;  a  is  a 
cross  pane,  b  a  straight  pane,  c  a  ball  pane,  and  so  on.  Hand-hammers  mostly  range 
between  1  and  4  lb.  in  weight ;  chipping  hammers,  h-lh  lb. ;  riveting  hammers,  5-2 lb.; 


19. 


\^-^-^ 


f 


eledge  hammers  not  exceeding  8  lb.  in  weight  are  "uphanded,"  i.e.  only  raised  to  a 
little  above  the  shoulder,  while  the  heavier  ones  (8-16  lb.)  are  "  swung"  in  a  complete 
circle.  The  machinists'  hammer  is  made  heavier  at  the  face  than  at  the  pane  end,  so^ 
that  the  hammer  will  naturally  assume  a  position  in  the  hand  with  the  face  downwards,, 
thus  relieving  the  workman  from  the  necessity  of  specially  forcing  it  into  that  position. 
In  using  a  hammer  it  is  essential  to  study  the  diflfercnce  between  a  sharp  blow  with  a 


FOEGING    AND    FINISHING. 


49 


light  liammcr  and  a  blow  blow  with  a  heavy  one:  the  formor  penetrates  farthest  and 
gives  least  lateral  pressure  ;  while  the  latter  penetrates  less  and  spreads  more  sideways. 

Cutting  Tools. — The  following  remarks  are  in  the  main  condensed  from  a  lecture  on 
Chisels  and  Chisel-shaped  Tools,  delivered  by  Joshua  Rose  before  the  Franklin  Institute, 
Philadelphia. 

In  Figs.  20  and  21  are  shown  the  shapes  in  wliich  flat  chisels  are  made.  The  diiferenco 
between  the  two  is  that,  as  the  cutting  edge  should  be  parallel  with  the  flats  on  the 
chisel,  and  as  Fig.  20  has  the 

-widest  flat,  it  is  easier  to  tell  20.  21.  22. 

with  it  when  the  cutting  edge 
and  the  flat  are  parallel ;  there- 
fore the  broad  flat  is  the  best 
guide  in  holding  the  chisel 
level  with  the  surface  to  bo 
chipped.  Either  of  these 
cliisels  is  of  a  proper  width  for 
wrought-iron  or  steel,  because 
chisels  nsed  on  these  metals 
take  all  the  power  to  drive  that 
can  be  given  with  a  hammer  of 
the  usual  proportions  for  heavy 
clipping,  which  is — weight  of 
hammer.  If  lb.;  length  of 
liammer  handle,  13  in. ;  the 
handle  to  be  held  at  its  end  and 
swinging  back  about  vertically 
over  the  shoulder. 

If  so  narrow  a  chisel  be  used 
on" cast-iron  or  brass,  with  full-force  hammer  blows,  it  will  break  out  the  metal  instead 
of  cutting  it,  and  the  break  may  come  below  the  depth  wanted  to  chip,  and  leave  ugly 
cavities.  So  for  these  metals  the  chisel  must  be  made  broader,  as  in  Fig.  22,  so  that 
the  force  of  the  blow  will  be  spread  over  a  greater  length  of  chisel  edge,  and  the  edge 
will  not  move  forward  so  much  at  each  blow,  therefore  it  will  not  break  the  metal  out. 

Another  advantage  is  that  the  broader  the  chisel  the  easier  it  is  to  hold  its  edge 
fair  with  the  work  surface  and  make  smooth  chipping.     The  chisel  point  must  be  made 


23. 


24. 


as  thin  as  possible,  the  thickness  shown  in  the  sketches  being  suitable  for  new  chisels. 
In  giiuding  the  2  facets  to  form  the  chisel,  be  careful  to  avoid  grinding  them  rounded, 
as  shown  in  a  in  the  magnified  chisel  ends  in  Fig.  23  ;  the  proper  way  is  to  grind  them 
flat,  as  at  ?>  in  the  sketch.  Make  the  angle  of  these  2  facets  as  acute  as  you  can,  because 
tlie  chisel  will  then  cut  easier. 


50 


Forging  and  Finishing. 


The  lidding  angle  at  c,  in  Fig.  24,  is  about  riglit  for  brass,  and  that  at  d  is  about 
right  for  steel.  The  difl'erence  is  that  with  hard  metal  the  more  acute  angle  dulls  too 
quickly. 

Considering  the  length  of  the  cutting,  it  may  for  heavy  chipping  be  made  straight, 
as  in  Fig.  20,  or  curved,  as  in  Fig.  22,  -which  is  the  best,  because  the  corners  are  relieved 
of  duty  and  are  therefore  less  liable  to  break.  The  advantage  of  the  curve  is  greatest 
in  fine  chipping,  because,  as  seen  in  Fig.  25,  a  thin  chip  can  be  taken  without  cutting 
■with  the  corners,  and  these  corners  are  exposed  to  the  eye  in  keeping  the  chisel  edge 
level  with  the  work  surface. 

In  any  case  you  must  not  grind  the  chisel  hollow  in  its  length,  as  in  Fig.  26,  or  as 
shown  exaggerated  in  Fig.  27,  because  in  that  case  the  corners  will  dig  in  and  cause  the 


25. 


chisel  to  be  beyond  control ;  besides  that,  there  will  be  a  force  that,  acting  on  the  wedge 
principle  and  in  the  direction  of  the  arrows,  will  operate  to  spread  the  corners  and 
break  them  off. 

Do  not  grind  the  facets  wider  on  one  side  than  on  the  other  of  the  chisel,  as  in  Fig.  28, 
because  in  that  case  the  fiat  of  the  chisel  will  form  no  guide  to  let  you  know  when 


31. 


the  cutting  edge  is  level  with  the  work  surface.  Nor  must  you  grind  it  out  of  square 
with  the  chisel  body,  as  in  Fig.  29,  because  in  that  case  the  chisel  will  be  apt  to  jump 
sideways  at  each  hammer  blow. 

A  quantity  of  metal  can  be  removed  quicker  by  using  the  cape  chisel  in  Fig.  30,  to 


FOEGING   AND  FINISHING. 


51 


first  cut  out  grooves,  as  at  a,h,  and  c  in  Fig.  31,  spacing  these  grooves  a  littlo  narrower 
apart  than  the  width  of  the  flat  chisel,  and  thus  relieving  its  corners.  It  is  necessary 
to  shape  the  end  of  this  chisel  as  at  a  and  h,  and  not  as  at  c,  as  in  Fig.  30,  so  as  to  bo 
able  to  move  it  sideways  to  guide  it  in  a  straight  line,  and  the  parallel  part  at  c  will 
interfere  with  this,  so  that  if  the  chisel  is  started  a  very  little  out  of  line  it  will  go 
still  farther  out  of  line,  and  cannot  bo  moved  sideways  to  correct  this. 

The  round-nosed  chisel,  Fig.  32,  must  not  bo  made  straiglit  on  its  convex  edge :  it 
may  be  straight  from  h  to  g,  but  from  g  to  the  point  it  must  be  bevelled  so  that  by 
altering  the  height  of  the  chisel  head  it  is  possible  to  alter  the  depth  of  the  cut. 

The  cow-mouthed  chisel,  Fig.  33,  must  be  bevelled  in  the  same  way,  so  that  when 


32. 


rPT] 


used  to  cut  out  a  round  corner,  as  at  I  in  Fig.  31,  you  can  move  the  head  to  the 
right  or  to  the  left,  and  thus  govern  the  depth  of  its  cut. 

The  oil  groove  chisel  in  Fig.  34  must  be  made  narrower  at  a  than  it  is  across  the 
curve,  as  it  will  wedge  in  the  groove  it  cuts. 

The  diamond-point  chisel  in  Figs.  35  and  36  must  be  shaped  to  suit  the  work, 
because  if  it  is  not  to  be  used  to  cut  out  the  corners  of  very  deep  holes,  you  can 
bevel  it  at  m  and  thus  bring  its  point  x  central  to  the  body  of  the  steel,  as  shown  by  the 
dotted  line  q,  rendering  the  corner  x  less  liable  to  break,  which  is  the  great  trouble  with 
this  chisel.  But  as  the  bevel  at  m  necessitates  the  chisel  being  leaned  over  as  at  y  in 
Fig.  31,  it  could  in  deep  holes  not  be  kept  to  its  cut ;  so  you  must  omit  the  bevel  at  m, 
and  make  that  edge  straight  as  at  r  in  Fig.  36. 

The  side  chisel  obeys  just  the  same  rule,  so  you  may  give  it  bevel  at  w  in  Fig.  37 
for  shallow  holes,  and  lean  it  over  as  at  z  in  Fig.  31,  or  make  the  side  vw  straight  along 
its  whole  length,  for  deep  ones ;  but  in  all  chisels  for  slots  or  mortices  it  is  desirable  to 
I  have,  if  the  circumstances  will  permit,  some  bevel  on  the  side  that  meets  the  work,  so 
that  the  depth  of  the  cut  can  be  regulated  by  moving  the  chisel  head. 

In  all  these  chisels,  the  chip  on  the  work  steadies  the  cutting  end,  and  it  is  clear  that 
the  nearer  you  hold  the  chisel  at  its  head  the  steadier  you  can  hold  it,  and  the  less 
the  liability  to  hit  your  fingers,  while  the  chipped  surface  will  be  smoother. 

To  take  a  chip  oflf  a  piece  of  wrought  iron,  if  it  is  a  heavy  chip,  stand  well  away 
jfrom  the  vice,  as  an  old  hand  would  do,  instead  of  close  to  it,  as  would  be  natural  in  an 
jtminstructed  beginner.  In  the  one  case  the  body  is  lithe  and  supple,  having  a  slight 
Iraotion  in  unison  with  the  hammer  ;  while  in  the  other  it  is  constrained,  and  not  only  feels 
but  looks  awkward.  If,  now,  you  wish  to  take  a  light  chip,  you  must  stand  nearer  to  the 
work,  so  that  you  can  watch  the  chisel's  action  and  keep  its  depth  of  ciit  level.  In 
both  cases  you  push  the  chisel  forward  to  its  cut  and  hold  it  as  steadily  as  you  can.    It 

E  2 


52 


Forging  and  Finishing, 


is  a  mistake  to  move  it  at  each  blow,  as  many  do,  because  it  cannot  be  so  accurately 
maintained  at  the  proper  height.  Ijighfc  and  quick  blows  are  always  necessary  for  the 
finishing  cuts,  whatever  the  kind  of  metal  may  be. 

With  the  side  chisel  there  must  be  a  bevel  made  at  the  end  in  order  to  enable  the 
depth  of  cut  to  be  adjusted  and  governed,  for  if  you  happened  to  get  the  straight  chisel 
too  deeply  into  its  cut,  you  cannot  alter  it,  and  unless  you  begin  a  new  cut  it  will 

35. 


Q  O 


«    i 


\ 


get  embedded  deeper,  and  will  finally  break.  But  with  this  side  chisel  (Fig.  37)  that 
is  slightly  bevelled,  you  can  regulate  the  depth  of  cut,  making  it  less  if  it  gets  too 
deep,  or  deeper  if  it  gets  too  shallow. 

The  chisel  that  is  driven  by  hammer  blows  may  be  said  to  be  to  some  extent  a 
connecting  link  between  the  hammer  and  the  cutting  tool,  the  main  difierence  being 
that  the  chisel  moves  to  the  work  while  the  work  generally  moves  to  the  cutting  tool. 
In  many  stone-dressing  tools  the  ciiisel  and  hammer  are  combined,  iaasmuch  as  that 
the  end  of  the  hammer  is  chisel  shaped,  an  example  of  this  kind  of  tool  being  given  in 
the  pick  that  flour  millers  use  to  dress  their  grinding  stones.  On  the  other  hand,  we 
may  show  the  connection  between  the  chisel  and  the  cutting  tool  by  the  fact  that  the 
wood-worker  uses  the  chisel  by  driving  it  with  a  mallet,  and  also  by  using  it  for  a 
cutting  tool  for  work  driven  in  the  lathe.  Indeed,  we  may  take  one  of  these  carpenters' 
chisels,  and  fasten  it  to  the  revolving  shaft  of  a  wood-planing  machine,  and  it  becomes 
a  planing-knife ;  or  we  may  put  it  into  a  carpenters'  hand  plane,  and  by  putting  to  the 
work  it  becomes  a  plane  blade.  In  each  case  it  is  simply  a  wedge  whose  end  is  made 
more  or  less  acute  so  as  to  make  it  as  sharp  as  possible,  while  still  retaining  strength 
enough  to  sever  the  material  it  is  to  operate  upon. 

lu  whatever  form  we  may  apply  this  wedge,  there  are  certain  well-defined  mecha- 
nical principles  that  govern  its  use.  Thus,  when  we  employ  it  as  a  hand  tool  its 
direction  of  motion  under  hammer  blows  is  governed  by  tlie  inclination  of  that  of  its 
faces  which  meets  the  strongest  side  of  the  work,  while  it  is  the  weakest  side  of  the 
material  that  moves  the  most  to  admit  the  wedge,  and,  therefore,  becomes  the  chip, 
cutting,  or  shaving.  In  Fig.  38,  for  example,  we  have  the  carpenters'  chisel  operating 
at  a  and  h  to  cut  out  a  recess  or  mortice,  and  it  is  seen  that  so  long  as  the  face  of  the 
chisel  that  is  next  to  the  work  is  placed  level  with  the  straight  surface  of  the  work,  the 


Forging  and  Finishing. 


53 


(leptli  of  eui  will  be  equal,  or,  in  other  words,  llio  line  of  motion  of  the  chisel  is  that  of 
the  chisel  face  that  lies  against  the  work.  At  c  and  cZ  is  a  chisel  with,  in  tho  one 
instance,  the  straight,  and  in  tho  other  the  bevelled  face  toward  the  work  surface.  In 
both  cases  the  cut  would  gradually  deepen  because  the  lower  surface  of  tho  chisel  is  not 
parallel  to  the  face  of  tho  work. 

If  now  we  consider  the  extreme  cutting  edge  of  the  chisel  or  wedge-shaped  toolsj,  it 
will  readily  occur  that  but  for  the  metal  behind  this  fine  edge  tho  shaving  or  cutting 
would  come  off  in  a  straight  ribbon,  and  that  the  bend  or  curl  that  the  cutting  assumes 
increases  with  the  angle  of  the  face  of  the  wedge  that  meets  the  cutting,  shaving,  ov 
chip.  For  example,  if  you  take  a  piece  of  lead,  and  with  a  penknife  held  as  at  a, 
Fig.  39,  cut  off  a  curl,  it  will  be  bent  to  a  large  curve ;  but  if  the  same  knife  is  held  as 
at  b,  it  will  cause  the  shaving  to  curl  iip  more.  It  has  taken  some  power  to  efl'ect  this 
extra  bending  or  curling,  and  it  is  therefore  desirable  to  avoid  it  as  far  as  possible.     For 


39. 


cc 


the  purpose  of  distinction,  the  face  of  the  chisel  which  meets  the  shaving  may  be 
called  the  top  face,  and  that  which  lies  next  the  main  body  of  the  work  the  bottom 
face.  Then  at  whatever  angle  these  2  faces  of  the  chisel  may  be  to  each  other,  and  in 
whatever  way  the  chisel  is  presented  to  the  work,  the  strength  of  the  cutting  edge 
depends  upon  the  angle  of  the  bottom  face  to  the  line  of  motion  of  the  chisel ;  and  this 
is  a  rule  that  applies  to  all  tools  embodying  the  wedge  principle,  whether  they  are 
moved  by  hand  or  machine.  Thus  in  Fig.  40  the  bottom  face  is  placed  at  an  angle  of 
80°  to  the  line  of  tool  motion,  which  is  denoted  by  the  arrow,  and  its  weakness  is 
obvious.  If  the  angle  of  the  top  face  to  the  line  of  tool  motion  is  determined  upon,  we 
may  therefore  obtain  the  strongest  cutting  edge  in  a  hand-moved  tool  by  causing  tho 
bottom  angle  to  lie  fiat  upon  the  work  surface.  But  in  tools  driven  by  machine  power, 
and  therefore  accurately  guided  in  their  line  of  motion,  it  is  preferable  to  kt  the  bottom 
face  clear  the  work  surface,  save  at  the  extreme  cutting  edge.  The  front  face  of  the 
tool  is  that  which  mainly  determines  its  keenness,  as  may  be  seen  from  Fig.  41,  in 
which  the  tool  is  differently  placed  with  relation  to  the  work,  that  at  a  being  obviously 
the  keenest  and  least  liable  to  break  from  the  strain  of  the  cutting  process. 

Drilling  and  Boring. — The  term  "  drilling  "  is  applied  to  the  operation  of  perforating 


54  Forging  and  Finishing. 

or  sinking  holes  in  solid  material,  -while  "  boring  "  is  confined  to  turning  out  annular  holes 
to  true  dimensions.  These  allied  processes  are  thus  succinctly  explained  by  Kichards  in 
his  excellent  manual  on  '  Workshop  Manipulation.'  In  boring,  tools  are  guided  by 
axial  support  independent  of  the  bearing  of  their  edges  on  the  material;  while  in 
drilling,  the  cutting  edges  are  guided  and  supported  mainly  from  their  contact  with  and 
bearing  on  the  material  drilled.  Owing  to  this  difference  in  the  manner  of  guiding 
and  supporting  the  cutting  edges,  and  the  advantages  of  an  axial  support  for  tools  in 
boring,  it  becomes  an  operation  by  which  the  most  accurate  dimensions  are  attainable, 
while  drilling  is  a  comparatively  imperfect  operation ;  yet  the  ordinary  conditions  of 
machine  fitting  are  such  that  nearly  all  small  holes  can  be  drilled  with  sufficient 
accuracy. 

Boring  may  be  called  internal  turning,  differing  from  external  turning,  because  of 
the  tools  perfoiming  the  cutting  movement,  and  in  the  cut  being  made  on  concave 
instead  of  convex  surfaces ;  otherwise  there  is  a  close  analogy  between  the  operations 
of  turning  and  boring.  Buring  is  to  some  extent  performed  on  lathes,  either  with 
boring  bars  or  by  what  is  termed  chuck-boring ;  in  the  latter,  the  material  is  revolved 
and  the  tools  are  stationary.  Boring  may  be  divided  into  three  operations  as  follows ; 
chuck-boring  on  latlies  ;  bar-boring  when  a  boring  bar  runs  on  points  or  centres,  and  is 
supported  at  the  ends  only ;  and  bar-boring  when  a  bar  is  supported  in  and  fed  through 
fixed  bearings.  The  principles  are  different  in  these  operations,  each  being  applicable 
to  certain  kinds  of  work.  A  workman  who  can  distinguish  between  these  plans 
of  boring,  can  always  determine  from  the  nature  of  a  certain  work  which  is  the  best 
to  adopt,  lias  acquired  considerable  knowledge  of  fitting  operations.  Chuck-boring  is 
employed  in  three  cases :  for  holes  of  shallow  depth,  taper  holes,  and  holes  that  are 
screw-threaded.  As  i^ieces  are  overhung  in  lathe-boring,  there  is  not  sufiicient  rigidity, 
either  of  the  lathe  spindle  or  of  the  tools,  to  admit  of  deej}  boring.  The  tools  being 
guided  in  a  straight  line,  and  capable  of  acting  at  any  angle  to  the  axis  of  rotation,  the 
facilities  for  making  tapered  holes  are  complete ;  and  as  the.  holes  are  stationary,  and  may 
be  instantly  adjusted,  the  same  conditions  answer  for  cutting  internal  screw-threads;  an 
operation  corresponding  to  cutting  external  screws,  except  that  the  cross  motions  of  the 
tool  slide  are  reversed.  The  second  plan  of  boring  by  means  of  a  bar  mounted  on 
points  or  centres  is  one  by  which  the  greatest  accuracy  is  attainable  ;  it  is,  like  chuck- 
boring,  a  lathe  operation,  and  one  for  which  no  better  machine  than  a  lathe  has  been 
devised,  at  least  for  the  smaller  kinds  of  work.  It  is  a  problem  whether  in  ordinary 
machine  fitting  there  is  not  a  gain  by  performing  all  boring  in  this  manner,  whenever 
the  rigidity  of  boring  bars  is  suSicient  without  auxiliary  supports,  and  when  the  bars 
can  pass  through  the  work.  Machines  arranged  for  this  kind  of  boring  can  be 
employed  in  turning  or  boring  as  occasion  may  require.  When  a  tool  is  guided  by 
turning  on  points,  the  movement  is  perfect,  and  the  straightness  or  parallelism  of  holes 
bored  in  this  manner  is  dependent  only  on  the  truth  of  the  carriage  movement.  This 
plan  of  boring  is  employed  for  small  steam  cylinders,  cylindrical  valve  seats,  and  in 
cases  where  accuracy  is  essential.  The  third  plan  of  boring  with  bars  resting  in 
bearings  is  more  extensively  practised,  and  has  the  largest  range  of  adaptation.  A 
feature  of  this  plan  of  boring  is  that  the  form  of  the  boring  bar,  or  any  imperfection 
in  its  bearings,  is  communicated  to  tJic  work  ;  a  want  of  straightness  in  the  bar  makes 
tapering  holes.  This,  of  course,  applies  to  cases  where  a  bar  is  fed  through  fixed 
bearings  placed  at  one  or  both  ends  of  a  hole  to  be  bored.  If  a  boring  bar  is  bent,  or 
out  of  truth  between  its  luarings,  the  diameter  of  the  hole  (being  governed  by  the 
extreme  sweep  of  the  cutters)  is  untrue  to  tlie  same  extent,  because  as  the  cutters  move 
along  and  come  nearer  to  the  bearings,  the  bar  runs  with  more  truth,  forming  a  tapering 
hole  diminishing  toward  the  rests  or  bearings.  The  same  rule  applies  to  some  extent 
in  chuck-boring,  the  form  of  the  lathe  spindle  being  communicated  to  holes  bored  ;  but 
lathe  spindles  are  presumed  to  be  quite  perfect  compared  with  boring  bars. 


Forging  and  Finishing. 


55 


The  prevailing  custom  of  casting  machine  frames  in  one  piece,  or  iu  as  few  pieces  as 
possible,  leads  to  a  great  deal  of  bar-boring,  most  of  which  can  be  performed  accurately 
enough  by  boring  bars  supported  iu  and  fed  through  bearings.  By  setting  uji 
temporary  bearings  to  support  boring  bars,  and  improvising  means  of  driving  and 
feeding,  most  of  the  boring  on  machine  frames  can  be  performed  on  floors  or  sole  plates 
and  independent  of  boring  machines  and  lathes.  There  are  but  few  cases  in  which  the 
importance  of  studying  the  jDrinciples  of  tool  action  is  more  clearly  demonstrated  than 
in  this  matter  of  boring  ;  even  long  practical  experience  seldom  leads  to  a  thorough 
understanding  of  the  various  problems  which  it  involves. 

Drilling  difiers  in  principle  from  almost  every  other  operation  in  metal  cutting.  The 
tools,  instead  of  being  held  and  directed  by  guides  or  spindles,  are  supported  mainly  by 
the  bearing  of  the  cutting  edges  against  the  material.  A  common  angular-pointed  drill 
is  capable  of  withstanding  a  greater  amount  of  strain  upon  its  edges  and  rougher  use 
than  any  other  cutting  implement  employed  iu  machine  fitting.  The  rigid  support 
which  the  edges  receive,  and  the  tendency  to  press  them  to  the  centre,  instead  of  to  tear 
them  away  as  with  other  tools,  allows  drills  to  be  used  when  they  are  imperfectly  shaped, 
improperly  tempered,  and  even  when  the  cutting  edges  are  of  unequal  length.  Most  of 
the  difiSculties  which  formerly  pertained  to  drilling  are  now  removed  by  machine- 
made  drills,  which  are  manufactured  and  sold  as  an  article  of  trade.  Such  drills  do  not 
require  dressing  and  tempering,  or  fitting  to  size  after  they  are  in  use,  make  true  holes, 
are  more  rigid  than  common  solid  shank  drills,  and  will  drill  to  a  considerable  depth 
without  clogging.  A  drilling  machine,  adapted  to  the  usual  requirements  of  a  machine 
fitting  establishment,  consists  essentially  of  a  spindle  arranged  to  be  driven  at  various 
speeds,  with  a  movement  for  feeding  the  drills  ;  a  firm  table  set  at  right  angles  to  the 
spindle,  and  arranged  with  a  vertical  adjustment  to  or  from  the  spindle ;  and  a  compound 
adjustment  in  a  horizontal  plane.  The  simplicity  of  the  mechanism  required  to  operate 
drilling  tools  is  such  that  it  has  permitted  various  modifications,  such  as  column  drills, 
radial  drills,  susi^ended  drills,  horizontal  drills,  bracket  drills,  multiple  drills,  and  others. 
Drilling,  more  than  any  other  operation  in  metal  cutting,  requires  the  sense  of  feeling, 
and  is  farther  from  such  conditions  as  admit  of  power  feeding.  The  speed  at  which  a 
drill  may  cut  without  heating  or  breaking  is  dependent  upon  the  manner  in  which  it  is 
ground,  and  the  nature  of  the  material  drilled ;  the  working  conditions  may  change  at 
any  moment  as  the  drilling  progresses,  so  that  hand  feed  is  most  suitable.     Drilling 


(^3 


machines  arranged  with  power  feed  for  boring  should  have  some  means  of  permanently 
disengaging  the  feeding  mechanism  to  prevent  its  use  in  ordinary  drilling. 

Drills  present  considerable  variety  in  size  and  shape,  but  representative  examples 
are  shown  in  Fig.  42  :  a  is  the  simplest  and  most  general  form ;  6  is  a  pin  drill,  which 
does  rapid  work  when  a  hole  for  the  reception  of  the  pin  has  been  first  made  with  a 
smaller  drill ;  c  is  an  American  production,  the  Morse  twist  drill,  which  far  surpasses 


56 


FOKGING    AND   FINISHING. 


all  others  in  working  capacity.  In  grinding  an  ordinary  drill  (a)  ready  for  use,  it  ia 
essential  to  see  that  the  cutting  edges  are  at  right  angles  to  each  other,  the  outside  faces 
of  the  blade  sliglitly  rounded,  and  the  point  as  small  and  fine  as  the  work  will  allow. 
If  these  conditions  are  neglected,  the  point  will  not  maintain  a  central  position,  and 
there  will  not  be  convenient  space  for  the  escape  of  the  chips.  In  pin  drills  it  is  abso- 
lutely necessary  to  have  the  first  hole  for  the  pin  quite  straight,  and  fitting  so  well  that 
the  pin  cannot  shake,  or  the  work  will  be  irregular ;  these  drills  are  not  easy  to  sharpen 
when  worn.     The  Morse  twist  drills  can  be  obtained  in  sets  of  standard  sizes. 

All  forms  of  drill  are  applied  by  the  aid  of  a  rotary  motion,  which  may  be  communi- 
cated by  the  ratcliet  brace,  of  which  several  forms  are  shown :  Fig.  43  is  a  universal 


43. 


u 


u. 


2^ 


J 


ball ;  Fig.  44,  a  self-feeding ;  Fig.  45,  a  treble-motion ;  and  Fig.  4G,  Calvert's  ratchet 
brace.  Figs.  47  to  49  are  drill  stocks  of  various  kinds,  differing  mainly  in  the  means 
by  which  suitable  pressure  is  secured. 


45. 


46. 


Swaging  Tools. — Figs.  50,  51,  illustrate  a  couple  of  forms  of  swaging  block,  which 
are  often  useful  for  shaping  a  piece  of  hot  metal  quickly  and  truly. 

Surfacing  Tools. — By  far  the  most  important  tool  used  in  perfecting  the  surface  effused 
or'cast  work  is  the  file.  It  is  sometimes  replaced  by  emery,  either  in  the  form  of  wheels 
or  as  powder  attached  to  cloth ;  and  is  often  supplemented  in  fine  work  by  one  of  the 
various  kinds  of  polishing  powder,  e.g.  chalk,  crocus,  putty  powder,  tripoli,  sand,  &c. 

It  has  been  remarked  that  the  most  important  point  to  be  decided  before  commencing 
filing  is  the  fixing  the  vice  to  the  correct  height  and  perfectly  square,  so  that  when  the 
work  to  be  operated  on  is  placed  in  the  vice  it  will  lie  level.  As  to  what  is  really  the 
correct  height  some  slight  diffi-rence  of  opinion  exists,  but  the  height  which  is  generally 
thought  right  is  such  that  the  "chops"  or  jaws  of  the  vice  come  just  below  the  elbow  of  the 
workman  when  he  is  at  his  place  in  front  of  the  vice.  Having  the  vice  fixed  properly, 
the  correct  position  to  assume  when  filing  is  tlie  next  consideration.  The  left  foot  should 
be  about  6  in.  to  left  and  6  in.  to  "  front  "  of  the  vice  leg  ;  the  right  foot  being  about 
30  in.  to  front,  that  is  to  say,  30  in.  away  from  the  board  in  a  straight  line  with  the  vice 


Forging  and  Finishing. 


57 


post.    This  position  gives  command  over  the  tool,  and  is  at  once  characteristic  of  a  good 
workman. 

The  file  must  be  grasped  firmly  in  the  right  hand  by  the  handle,  and  it  is  as  ■well 
here  to  make  a  few  parenthetical  remarks  on  handles ;  they  should  always  be  propor- 


47. 


48. 


tionate  to  the  files  to  which  they  are  fitted,  and  the  hole  in  the  handle  should  be 
properly  squared  out  to  fit  the  "tang"  by  means  of  a  small  "  float"  made  from  a  small 
bar  of  steel,  similar  to  those  used  by  plane-makers  and  cabinet-makers.  The  handles 
should  always  have  good  strong  ferrules  on  them,  and  the  files  should  be  driven  home 


50. 


51. 


quite  straight  and  firm,  so  that  there  is  no  chance  of  the  tool  coming  out.  Each  tool 
should  have  its  handle  permanently  fixed ;  it  is  very  false  economy,  considering  the 
price  of  handles  is  about  9d.  per  dozen,  to  be  continually  changing.  The  left  hand 
must  just  hold  the  point  of  the  file  lightly,  so  as  to  guide  it ;  and  in  taking  the  forward 
cut  a  fairly  heavy  pressure  must  be  applied,  proportionate  to  the  size  of  the  tool  iti  use 
and  the  work  being  done.     Amateurs  who  have  never  received  any  practical  instruction 


58  Forging  and  Finishing. 

in  the  use  of  files  generally  liave  a  bad  habit  of  pressing  heavily  on  the  tool  continuously 
during  both  forward  and  backward  stroke,  and  at  the  same  time  work  far  too  quickly. 
These  habits  combined  will  almost  invariably  spoil  whatever  is  operated  on,  producing 
surfaces  more  or  less  rounding,  but  never  flat. 

The  art  of  filing  a  flat  surface  is  not  to  be  learned  without  considerable  practice,  and 
long  and  attentive  practice  is  necessary  ere  the  novice  will  be  able  to  creditably  accom- 
plish one  of  the  most  difficult  operations  which  fall  to  every-day  engineering  work,  and 
one  which  even  the  most  professionally  taught  workman  does  not  always  succeed  in.  The 
file  must  be  used  with  long,  slow,  and  steady  strokes,  taken  right  from  point  to  tang, 
moderate  pressure  being  brought  to  bear  during  the  forw^ard  stroke ;  but  the  file  must  be 
relieved  of  all  pressure  dui-ing  the  return  stroke,  otherwise  the  teeth  will  be  liable  to  be 
broken  off,  just  in  the  same  manner  that  the  point  of  a  turning  tool  would  be  broken  if 
the  lathe  were  turned  the  wrong  way.  It  is  not  necessary  to  lift  the  file  altogether  off 
the  work,  but  it  should  only  have  its  bare  weight  pressing  during  the  back  stroke.  One 
of  the  chief  difficulties  in  filing  flat  is  that  the  arms  have  a  tendency  to  move  in  arcs 
from  the  joints,  but  this  will  be  conquered  by  practice. 

A  piece  of  work  which  has  been  filed  up  properly  will  present  a  flat,  even  surface, 
with  the  file  marks  running  in  straight  parallel  lines  from  side  to  side.  Each  stroke  of 
the  file  will  have  been  made  to  obtain  a  like  end,  whereas  work  which  has  been  turned 
out  by  a  careless  or  inexperienced  workman  will  often  bear  evidence  that  each  stroke  of 
the  file  was  made  with  utter  disregard  to  all  others,  and  the  surface  will  be  made  up  of 
an  unlimited  number  of  facets,  varying  in  size,  shape,  and  position. 

There  is  considerable  skill  required  to  "  get  up  "  surfaces  of  large  area  by  means 
of  files  alone,  more  especially  when  these  surfaces  are  required  to  be  accurately  flat. 
The  method  of  preparing  surface  plates,  as  detailed  by  Sir  Joseph  Whitworth,  is 
most  valuable  information  to  any  one  desirous  of  excelling  in  this  particular  branch 
of  practical  handicraft,  and  those  interested  should  get  Whitworth's  pamphlet  entitled 
'  Plane  Bletallic  Surfaces,  and  the  Proper  Mode  of  Preparing  Them.'  In  large  engi- 
neering works,  filing  is  superseded  by  the  planing  and  shaping  machines  for  almost  all 
work  of  any  size.  The  speed  and  accuracy  of  the  planing  machine  cannot  be  approached 
by  the  file  when  there  is  any  quantity  of  material  to  be  removed,  and  files  are  only 
used  for  the  purpose  of  ' '  fitting  "  and  to  smooth  up  those  parts  which  are  inaccessible 
to  the  planing  tool.  However,  a  planing  machine  is  one  of  those  expensive  and  heavy 
pieces  of  machinery  usually  beyond  the  reach  of  amateurs  and  "  small  masters  " ;  it 
therefore  becomes  necessary  to  learn  how  to  dispense*  with  its  valuable  aid. 

Cast  iron  usually  forms  the  bulk  of  the  material  used  by  engineers.  The  hard  out- 
side skin  on  cast  iron,  and  the  sand  adhering  to  its  surface,  make  it  somewhat  formidable 
to  attack.  If  a  new  file  is  used  for  the  purpose  it  will  be  assuredly  spoiled  and  with 
no  gain;  for  one  ^Yhich  has  been  very  nearly  worn  out  will  be  almost  as  effective, 
and  will  not  be  much  deteriorated  by  the  use  to  which  it  is  put.  There  are  several 
ways  of  removing  the  "  bark  " — e.  g.  the  castings  may  be  "  pickled  " — that  is,  immersed 
in  a  bath  of  sulphuric  acid  and  water  for  a  couple  of  days ;  this  will  dissolve  the 
outer  crust  of  the  casting,  and  liberate  the  sand  adhering  to  the  surface  ;  another 
plan  is  to  remove  a  stratum  of  the  casting  from  that  part  which  has  to  be  filed,  by 
means  of  a  chipping  chisel,  and  this  is  a  very  good  plan  where  much  material  has 
to  be  removed  from  any  particular  part  of  a  large,  unwieldy  piece  of  machinery, 
though  some  practice  will  be  required  with  the  hammer  and  chisel  before  they  can  be 
used  satisfactorily. 

The  best  plan  to  follow  is  probably  this : — First  brush  the  casting  thoroughly — 
scrub  it — with  a  hard  brush  ;  this  will  rub  off  the  loose  sand  ;  then  take  an  old  file,  and 
file  away  steadily  at  the  skin  till  you  come  to  a  surface  of  pure  metal.  Having  by  this 
time  removed  those  parts  which  spoil  files,  the  "  old  file,"  with  which  but  slow  progress 
is  made,  can  be  changed  for  a  better  one,  and  the  best,  as  well  as  the  most  economical. 


FOKGING   AND   FINISHING.  59 

will  be  one  which  has  been  nsed  for  filing?  brass  till  it  has  become  too  much  worn  for 
that  material ;  such  a  file  is  in  lirst-class  condition  for  working  on  cast  iron  (when 
cleaned  of  its  sandy  skin),  and  when  worn  out  on  that  it  will  serve  admirably  for  steid. 

When  it  is  necessary  to  file  up  a  small  surface — say  2  in.  or  3  in.  square — the  file 
must  be  applied  in  continually  changing  directions,  not  always  at  right  angles  to  the 
chops  of  the  vice,  as,  though  the  work  might  be  made  perfectly  straight  in  that 
direction,  yet  there  would  not  be  any  means  of  assuring  a  like  result  on  that  part 
lying  parallel  to  the  jaws.  "When  the  surface  is  fairly  flat,  the  file  should  be  applied 
diagonally  both  ways ;  thus  any  hollow  or  high  places  otherwise  unobservable  will 
be  at  once  seen,  without  the  aid  of  straight-edges,  &c.  This  method  of  cros^sing  the 
file  cuts  from  corner  to  corner  is  recommended  in  all  cases,  and  the  file  should  invari- 
ably travel  right  across  the  work,  using  the  whole  length  of  the  file,  not  just  an  inch 
or  so  at  some  particular  part,  as  is  too  often  the  case.  When  in  use,  the  file  must  be 
held  quite  firmly,  yet  not  so  rigid  that  the  operator  cannot  feel  the  work  as  it  pro- 
gresses ;  the  sense  of  touch  is  brought  into  use  to  a  far  greater  extent  than  would  be 
imagined  by  the  inexperienced,  and  a  firm  grasp  of  the  tool,  at  the  same  time  preserv- 
ing a  light  touch  to  feel  the  work,  is  an  essential  attribute  of  a  good  filer. 

In  filing  out  mouldings  and  grooves  which  have  sections  resembling,  more  or  less, 
parts  of  a  circle,  a  special  mode  of  handling  the  file  becomes  requisite.  The  files  used 
are  generally  rats'-tails  or  half-rounds,  and  these  are  not  used  with  the  straightforward 
stroke  so  necessary  in  wielding  the  ordinary  hand-files,  but  a  partial  rotary  motion — a 
sort  of  twist  axially — is  given  to  the  file  at  each  stroke,  and  this  screw-like  tendency, 
given  alternately  from  right  to  left,  and  vice  versa,  serves  to  cross  the  file  cuts  and  regu- 
late the  truth  of  the  hollow. 

With  regard  to  cleaning  tools  which  have  become  clogged  up  with  minute  particles 
of  metal,  dirt,  and  grease,  files  which  are  in  that  state  are  not  fit  to  use,  and  the  follow- 
ing directions  will  enable  any  one  to  keep  them  in  proper  order.  The  most  generally 
used  tool  for  cleaning  files  is  the  scratch  brush  ;  but  this  is  not  very  efiicient  in  remov- 
ing those  little  pieces  which  get  firmly  embedded  and  play  havoc  with  the  work.  File 
cards  are  also  used  ;  they  are  made  by  fixing  a  quantity  of  cards— such  as  a  pack  of 
playing  cards — together  by  riveting,  or  screwing  to  a  piece  of  wood.  These  file  cards 
are  used  in  the  same  way  as  the  scratch  brushes,  i.  e.  transversely  across  the  file  in  the 
direction  of  its  "  cuts,"  and  though  neither  tool  produces  much  efi'ect  yet  they  are  both 
often  used.  ^Tien  files  have  become  clogged  up  with  oil  and  grease,  the  best  plan  is 
to  boil  them  for  a  few  minutes  in  some  strong  soda  water  ;  this  will  dissolve  the  grease 
and,  as  a  rule,  set  most  of  the  dirt  and  filings  free  ;  a  little  scrubbing  with  an  old  tooth 
brush  will  be  beneficial  before  rinsing  the  files  in  boiling  water  and  drying  them  before 
the  fire.  These  methods  will  prove  effective  in  removing  the  ordinary  accumulation 
of  dirt,  &c.,  in  files,  but  those  "  pins  "  which  are  so  much  to  be  dreaded  when  finishing 
work  can  only  be  removed  by  being  picked  out  with  a  scriber  point,  or,  what  is  better, 
a  piece  of  thin,  very  hard,  sheet  brass,  by  means  of  which  they  can  be  pushed  out  very 
easily.  These  "  pins  "  may  be  to  a  certain  extent  avoided  by  using  chalk  on  the  file, 
if  it  is  used  dry,  or  a  drop  or  two  of  oil  will  sometimes  help  matters. 

With  regard  to  finishing  filed  work,  such  as  has  to  be  made  particularly  presentable 
to  the  eye,  there  are  many  ways  of  polishing,  burnishing,  &c.,  but,  properly  speakmg, 
tliat  is  not  filing.  There  is  much  beauty  in  well-finished  work,  perfectly  square  and 
smooth,  as  left  by  the  file,  untouched  by  any  polishing  materials;  in  such  work  the 
filing  must  be  got  gradually  smoother  by  using  progressively  files  of  finer  cut,  and,  when 
the  work  is  deemed  sufficiently  finely  finished  for  the  purpose,  the  lines  should  bo 
carefully  equalized  by  "  draw-filing,"  that  is,  the  file  is  held  in  both  hands,  in  a  manner 
similar  to  a  spoke-shave,  and  drawn  over  the  work  in  the  same  way,  producing  a  series 
of  fine  parallel  lines. 

Screw-cutting  Tools.— These  are  intended  for  cutting  screw  threads  in  circular  work, 


60 


Forging  and  Finishing, 


such  as  on  the  outside  of  pipes  or  rods,  and  in  the  holes  cut  in  solid  work,  for  the 
purpose  of  making  screwed  joints.  Figs.  52-G3  show  a  double-handed  screw  stock 
with  4  pairs  of  dies,  and  4  each  of  taper  and  plug  taps ;  Fig.  64  is  a  clock  screw  plate  ; 
Fig.  65,  a  double-handed  screw  plate  with  taps ;  Fig,  66,  "Whitworth's  screw  stock. 


r.n. 


5-1.  ss. 


56. 


67. 


68, 


Fig.  67  illustrates  the  centre  gauge  for  grinding  and  setting  screw  tools,  and  the 
various  ways  of  using  it.  At  a  is  sliown  the  manner  of  gauging  the  angle  to  which  a 
lathe  centre  should  be  turned ;  at  h  the  angle  to  Avhich  a  screw  thread  cutting  tool 


3 


should  be  ground ;  at  c  the  correctness  of  the  angle  of  a  screw  thread  already  cut.  At 
d,  the  shaft  with  a  screw  thread  is  supposed  to  be  held  in  the  centres  of  a  lathe,  and  by 
applying  tlie  gauge,  as  at  d  or  e,  the  thread  tool  can  be  set  at  right  angles  to  the  shaft 


64. 


65. 


and  then  fastened  in  place  by  the  screw  in  tool  post,  thereby  avoiding  imperfect  or 
leaning  threads.  At  f  (j  the  manner  of  setting  the  tool  for  cutting  inside  threads  is 
illustrated.     The  angle  used  in  this  gauge  is  55°.     The  4  divisions  upon  the  gauge  of 


Forging  and  Finishing. 


61 


14,  20,  24,  and  32  parts  to  the  inch  are  very  useful  in  measurinf^  the  number  of  threads 
to  the  inch  of  taps  and  screws.     The  cost  of  the  gauge  is  only  28.  3ri. 

For  extensive  operations  a  number  of  small  machines  are  made  for  cuttin"  threads 
in  bolta  and  in  nuts.  " 


66. 


67. 


/ 


> 


Forging. — Forging  metal  consists  in  raising  it  to  a  high  temperature  and  hammering 
it  into  any  form  that  may  be  required.  Good  wrought  irou  may  be  seriously  injured  by 
■want  of  care  or  skill  in  forging  it  to  dififerent  shapes.  Eepeated  heating  and  reworking 
increases  the  strength  of  the  iron  up  to  a  certain  point ;  but  overheating  may  ruin  it ; 
the  iron  should  therefore  be  brought  to  the  required  shape  as  quickly  as  possible.  Tlie 
form  given  to  forgings  is  also  important ;  there  should  be  no  sudden  change  in  the 
dimensions — angles  should  be  avoided — the  larger  and  thicker  parts  of  a  forging  sliould 
-gradually  merge  by  curves  into  the  smaller  parts.  Experiments  have  shown  that  the 
■continuity  of  the  fibres  near  the  surface  should  be  as  little  interrupted  as  possible  ;  in 


62  FOEGING   AND   FINISHING. 

other  words,  that  the  fibres  near  the  surface  should  lie  in  layers  parallel  to  the  surface. 
If  wrought  iron  be  "  burnt,"  i.  c.  raised  to  too  high  a  temperature,  its  tensile  strength 
and  ductility  are  both  seriously  reduced.  These  qualities  may,  however,  be  to  a  great 
extent  restored  by  carefully  reheating  and  reroUing  the  iron.  Forging  steel  requires  still 
more  care  in  order  to  avoid  overheating.  Each  variety  of  steel  diflers  as  to  the  heat  to 
which  it  can  safely  be  raised.  Shear  steel  will  stand  a  white  heat ;  blister  steel  a 
moderate  heat ;  cast  steel  a  bright  red  heat. 

Welding. — This  is  the  process  by  which  2  pieces  of  metal  are  joined  together  with 
the  aid  of  heat.  Tiiere  are  several  forms  of  "  weld."  The  principles  upon  which  the 
welding  of  metals  depends  are  here  given.  In  welding  generally,  the  surfaces  of  the 
pieces  to  be  joined,  having  been  shaped  as  required  for  the  particular  form  of  weld,  are 
raised  to  a  high  temperature,  and  covered  with  a  flux  to  prevent  oxidation.  They  are 
then  brought  into  intimate  contact  and  well  hammered,  by  which  they  are  reduced  to 
their  original  dimensions,  the  scale  and  flux  are  driven  out,  and  the  strength  of  the  iron 
is  improved. 

Wrought  iron. — The  property  of  welding  possessed  by  wrought  iron  is  due  to  its 
continuing  soft  and  more  or  less  pasty  through  a  considerable  range  of  temperature 
below  its  melting  point.  When  at  a  white  heat,  it  is  so  pasty  that  if  2  pieces  be  firmly 
pressed  together  and  freed  from  oxide  or  other  impurity  they  unite  intimately  and  firmly. 
The  flux  used  to  remove  the  oxide  is  generally  sand,  sometimes  salt. 

Steel. — The  facility  with  which  steel  may  be  welded  to  steel  diminishes  as  the  metal 
approximates  to  cast  iron  with  respect  to  the  proportion  of  carbon  ;  or,  what  amounts  to 
the  same  thing,  it  increases  as  the  metal  approximates  to  wrought  iron  with  respect  to 
absence  of  carbon.  Hence  in  welding  together  2  pieces  of  steel — cxteris  imrihus — the 
more  nearly  their  melting  points  coincide— and  these  are  determined  by  the  amount  of 
carbon  they  contain— the  less  should  be  the  difficulty.  (Percy.)  Puddled  steel  welds 
ffery  indiff"erently,  and  so  does  cast  steel  containing  a  large  percentage  of  carbon.  The 
mild  cast  steels,  also  shear  and  blister  steel,  can  be  welded  with  ease.  In  welding  cast 
steel,  borax  or  sal-ammoniac,  or  mixtures  of  them,  are  used  as  fluxes.  Another  used 
for  mining  drills  in  America  is  a  mixture  of  6  qt.  powdered  limestone  and  1  qt.  sulphur ; 
heat  very  carefully  with  frequent  turnings,  take  from  the  fire  and  brush  with  a  short 
besom,  dip  into  the  mixture,  and  return  to  the  fire,  4  or  5  times,  before  the  heat  is  on. 
(See  also  Workshop  Eeceipts,  Third  Series,  pp.  293-303.) 

Steel  to  Wrought  Iron.— If  the  melting  points  of  2  metals  sensibly  difier,  then  the 
welding  point  of  the  one  may  be  near  the  melting  point  of  the  other,  and  the  difierence 
in  the  degree  of  plasticity,  so  to  speak,  between  the  2  jjieces  may  be  so  considerable  that 
when  they  are  brought  under  the  hammer  at  the  welding  point  of  the  least  fusible,  the 
blow  will  produce  a  greater  effect  upon  the  latter,  and  create  an  inequality  of  fibre. 
This  constitutes  the  difficulty  in  welding  steel  to  wrought  iron.  A  difference  at  the 
rate  of  expansion  of  the  2  pieces  to  be  welded  produces  unequal  contraction,  which  is  a 
manifest  disadvantage.  (Percy.)  Hard  cast  steel  and  wrougiit  iron  diff'er  so  much  in 
their  melting  points  that  they  can  hardly  be  welded  together.  Blister  and  shear  steel, 
or  any  of  the  milder  steels,  can,  however,  be  welded  to  wrought  iron  with  ease,  care  being 
taken  to  raise  the  iron  to  a  higher  temperature  than  the  steel,  as  the  welding  point 
of  the  latter  is  lower  is  consequence  of  its  greater  fusibility. 

Tem^jerm*/.— According  to  Richards,  an  excellent  authority  on  the  subject,  no  one 
has  been  able  to  explain  clearly  why  a  sudden  change  of  temperature  hardens  steel,  nor 
why  it  assumes  various  shades  of  colour  at  different  degrees  of  hardness  ;  we  only  know 
the  fact.  Every  one  who  uses  tools  should  understand  how  to  temper  them,  whether 
they  be  for  iron  or  wood.  Experimenting  with  tempered  tools  is  the  only  means  of 
determining  the  proper  degree  of  hardness,  and  as  smiths,  except  with  their  own  tools, 
have  to  rely  upon  the  explanations  of  others  as  to  proper  hardening,  it  follows  that 
tempering  is  generally  a  source  of  complaint.     Tempering,  as  a  term,  is  used  to  com- 


Forging  and  Finishing.  63 

prehend  both  hardening  and  drawing;  as  a  process,  it  depends  mainly  upon  judgment 
instead  of  skill,  and  has  no  such  connection  with  forghig  as  to  hu  performed  by  smiths 
only.  Tempej'ing  requires  a  diftVrent  lire  from  those  employed  in  forging,  and  also 
more  care  and  precision  than  blacksmiths  can  exercise,  unless  there  arc  furnaces  and 
baths  especially  arranged  for  tempering  tools.  A  difficulty  which  arises  in  Imrdening 
tools  is  because  of  the  contraction  of  the  steel  which  takes  place  in  proportion  to  the 
change  of  temperature ;  and  as  the  time  of  cooling  is  in  proportion  to  the  thickness  or  size 
of  a  piece,  it  follows,  of  course,  that  there  is  a  great  strain  and  a  tendency  to  break  the 
thinner  parts  before  the  thicker  parts  have  time  to  cool ;  this  strain  may  take  place  from 
cooling  one  side  first,  or  more  rapidly  than  another. 

The  following  propositions  in  regai-d  to  tempering  comprehend  the  main  points  to  be 
observed  : — (1)  The  permanent  contraction  of  steel  in  tempering  is  as  the  degree  of  liard- 
ness  imparted  to  it  by  the  bath.  (2)  The  time  in  which  the  contraction  takes  place  is  as 
the  temperature  of  the  bath  and  the  cross  section  of  the  piece  ;  in  other  words,  the  heat 
passes  off  gradually  from  the  surface  to  the  centre.  (3)  Thin  sections  of  steel  tools, 
being  projections  from  the  mass  whicli  support  the  edges,  are  cooled  first,  and  if  provision 
is  not  made  to  allow  for  contraction  they  are  torn  asunder. 

Tlie  main  point  in  hardening,  and  the  most  that  can  be  done  to  avoid  irregular 
contraction,  is  to  apply  the  bath  so  that  it  will  act  fii'st  and  strongest  on  the  thickest 
parts.  If  a  piece  is  tapering  or  in  the  form  of  a  wedge,  the  thick  end  should  enter  the 
bath  first ;  a  cold  chisel,  for  instance,  that  is  wide  enough  to  endanger  cracking  should  be 
put  into  the  bath  with  the  head  downward.  The  upflow  of  currents  of  warmed  water  is 
a  common  cause  of  irregular  cooling  and  springing  of  steel  tools  in  hardening;  the  water 
that  is  heated  rises  vertically,  and  the  least  inclination  of  a  piece  from  a  perpendicular 
position  allows  a  warm  current  to  flow  up  one  side.  The  most  effectual  means  of 
securing  a  uniform  effect  from  a  tempering  bath  is  by  violent  agitation,  either  of  the  bath 
or  the  piece  ;  this  also  adds  to  the  rapidity  of  cooling.  The  effect  of  tempering  batlis  is 
as  their  conducting  power  ;  chemicals,  except  as  they  may  contribute  to  the  conducting 
properties  of  a  bath,  may  safely  be  disregarded.  For  batlis,  cold  or  ice  water  loaded 
with  salt  for  extreme  hardness,  and  warm  oil  for  tools  that  are  thin  and  do  not  require  to 
be  very  hard,  are  the  two  extremes  outside  of  which  nothing  is  required  in  ordinary 
practice.  In  the  case  of  tools  composed  partly  of  iron  and  partly  of  steel,  steel  laid  as  it  is 
called,  the  tendency  to  crack  in  hardening  may  be  avoided  in  most  cases  by  hammering 
the  steel  edge  at  a  low  temperature  until  it  is  so  expanded  that  when  cooled  in 
hardening  it  will  only  contract  to  a  state  of  rest  and  correspond  to  the  iron  part;  the 
same  result  may  be  produced  by  curving  a  piece,  giving  convexity  to  the  steel  side 
before  hardening. 

Tools  should  never  be  tempered  by  immersing  their  edges  or  cutting  parts  in  the 
bath,  and  then  allowing  the  heat  to  "  run  down  "  to  attain  a  proper  temper  at  the  edge. 
Tools  so  hardened  have  a  gradually  diminishing  temper  from  their  point  or  edge,  so 
that  no  part  is  properly  tempered,  and  they  require  continual  rehardeniug,  which  spoils 
the  steel ;  besides,  the  extreme  edge,  the  only  part  which  is  tempered  to  a  proper 
shade,  is  usually  spoiled  by  heating,  and  must  be  ground  away  to  begin  with.  No 
latheman  who  has  once  had  a  set  of  tools  tempered  throughout  by  slow  drawing,  either 
in  an  oven,  or  on  a  hot  plate,  will  ever  consent  to  point  hardening  afterwards.  A  plate 
of  iron  2-2|  in.  thick,  placed  over  the  top  of  a  tool-dressing  fire,  makes  a  convenient 
arrangement  for  tempering  tools,  besides  adding  greatly  to  the  convenience  of  slow 
heating,  which  is  almost  as  important  as  slow  drawing.  Richards  has  by  actual 
experiment  determined  that  the  amount  of  tool  dressing  and  tempering,  to  say  nothing 
of  time  wasted  in  grinding  tools,  may  in  ordinary  machine  fittings  be  reduced  one- 
third  by  "  oven  tempering." 

As  to  the  shades  that  appear  in  drawing  temper,  or  tempering  it  is  sometimes  called, 
it  is  quite  useless  to  repeat  any  of  the  old  rules  about  "  straw  colour,  violet,  orange,  blue," 


64  Forging  and  Finishing. 

and  so  on  ;  the  learner  knows  as  much  after  such  instruction  as  before.  The  shades  of 
temper  must  be  seen  to  be  learned,  and  as  no  one  is  likely  to  have  use  for  such 
knowledge  before  having  opportunities  to  see  tempering  performed,  the  following  plan  is 
suggested  for  learning  the  different  shades.  Procure  8  pieces  of  cast  steel  about  2  in. 
long  by  1  in.  wide  and  -|  in.  thick,  heat  them  to  a  high  red  heat  and  drop  them  into  a 
salt  bath ;  preserve  one  without  tempering  to  show  the  white  shade  of  extreme  hardness, 
and  f)olish  one  side  of  each  of  the  remaining  7  pieces  ;  then  give  them  to  an  experienced 
■workman  to  be  drawn  to  7  varying  shades  of  temper  ranging  from  the  white  piece  to  the 
daik-blue  colour  of  soft  steel.  On  the  backs  of  these  pieces  .labels  can  be  pasted  describ- 
ing the  technical  names  of  the  shades  and  the  general  uses  to  which  tools  of  correspond- 
ing hardness  are  adapted.  This  will  form  an  interesting  collection  of  specimens  and 
accustom  the  eye  to  the  various  tints,  which  after  some  experience  will  be  instantly 
recognized  when  seen  separately. 

It  may  be  remarked  as  a  general  rule  that  the  hardness  of  cutting  tools  is  "  inverse 
as  the  hardness  of  the  material  to  be  cut,"  which  seems  anomalous,  and  no  doubt  is  so, 
if  nothing  but  the  cutting  properties  of  edges  is  considered ;  but  all  cutting  edges  are 
subjected  to  transverse  strain,  and  tiie  amount  of  this  strain  is  generally  as  the  hardness 
of  the  material  acted  upon  ;  hence  the  degree  of  temper  has  of  necessity  to  be  such  as  to 
guard  against  breaking  the  edges.  Tools  for  cutting  wood,  for  example,  are  harder  than 
those  usually  employed  for  cutting  iron ;  for  if  iron  tools  were  always  as  carefully  formed 
and  as  carefully  used  as  those  employed  in  cutting  wood,  they  could  be  equally  hard. 
('  Workshop  Manipulation.') 

Steel  plunged  into  cold  water  when  it  is  itself  at  a  red  heat  becomes  excessively  hard. 
The  more  suddenly  the  heat  is  extracted  tiie  harder  it  will  be.  This  process  of 
"  hardening,"  however,  makes  the  steel  very  brittle,  and  in  order  to  make  it  tough 
enough  for  most  purposes  it  has  to  be  "  tempered."  The  process  of  tempering  depends 
upon  another  characteristic  of  steel,  which  is  that  if  (after  hardening)  the  steel  be 
reheated,  as  the  heat  increases,  the  hardness  diminishes.  In  order  then  to  produce  steel 
of  a  certain  degree  of  toughness  (without  the  extreme  hardness  which  causes  brittleness), 
it  is  gradually  reheated,  and  then  cooled  when  it  arrives  at  that  temperature  which 
experience  has  shown  will  produce  the  limited  degree  of  hardness  required.  Heated 
steel  becomes  covered  with  a  thin  film  of  oxidation,  which  grows  thicker  and  changes  in 
colour  as  the  temperature  rises.  The  colour  of  this  film  is  therefore  an  indication  of  the 
temperature  of  the  steel  upon  which  it  appears.  Advantage  is  taken  of  this  change  of 
colour  in  the  process  of  tempering,  which  for  ordinary  masons'  tools  is  conducted  as 
follows  : — The  workman  places  the  point  or  cutting-end  of  the  tool  in  the  fire  till  it  is  of 
a  bright-red  heat,  then  hardens  it  by  dipping  the  end  of  the  tool  suddenly  into  cold 
water.  He  then  immediately  withdraws  the  tool  and  cleans  off  the  scale  from  the  point 
by  rubbing  it  on  the  stone  hearth.  He  watches  it  while  the  heat  in  the  body  of  the 
tool  returns,  by  conduction,  to  the  point.  The  point  thus  becomes  gradually  reheated, 
and  at  last  he  sees  that  colour  appear  which  he  knows  by  experience  to  be  an  indication 
that  the  steel  has  arrived  at  the  temperature  at  which  it  should  again  be  dipped.  He 
then  plunges  the  tool  suddenly  and  entirely  into  cold  water,  and  moves  it  about  till  the 
heat  has  all  been  extracted  by  the  water.  It  is  important  that  considerable  motion  should 
be  given  to  the  surface  of  the  water  while  the  tool  is  plunged  in,  after  tempering,  other- 
wise there  will  be  a  sharp  straight  line  of  demarcation  between  the  hardened  part  and 
the  remainder  of  the  tool,  and  the  metal  will  be  liable  to  snap  at  this  point. 

In  very  small  tools  there  is  not  sufficient  bulk  to  retain  the  heat  necessary  for  con- 
duction to  the  point  after  it  has  been  dipped.  Such  tools,  therefore,  are  heated, 
quenched,  rubbed  bright,  and  laid  upon  a  hot  plate  to  bring  them  to  the  required 
temperature  and  colour  before  being  finally  quenched.  In  some  cases,  the  articles  so 
heated  are  allowed  to  cool  slowly  in  the  air,  or  still  more  gradually  in  sand,  ashes,  or 
powdered  charcoal.    The  effect  of  cooling  slowly  is  to  produce  a  softer  degree  of  temper. 


Forging  and  Finishing.  65 

The  following  tabic  shows  the  temperature  at  which  the  steel  should  bo  suddenly 
cooled  in  order  to  produce  the  hardness  requireil  for  different  descriptions  of  tools.  It 
also  shows  the  colours  which  indicate  that  the  reciuired  temperature  has  been  reached  : — 

Colour  of  Film.  \'^t.'  Nature  of  Tool. 

Very  pale  straw  yellow  ..  430°     Lancets  and  tools  for  metal. 

A  shade  of  darker  yellow  ,.  440'°     Razors  and  do. 

Darker  straw  colour  . .  . .  470°     Penknives. 

Still  darker  straw  yellow  ..  490°     Cold  chisels  fur  cutting  iron,  tools  for  wood. 

Brownish  yellow         ..  ..  500°  (Hatchets,  plane  irons,  pocket  knives,  chipping 

Yellow  tinged  with  purple   . .     520°  L  ''^]'^^''  f  ^■^'  '^'^- 

1  Do.  do.  and  tools  tor  working  granite. 

Light  purple  ..          ..          ..  530°  ")  Swords,  watch-springs,  tools   for   cutting   sand- 
Dark  purple    ..          ..          ..  550°  /    stone. 

Dark  blue        ..  ..  ..  570°     Small  saws. 

Pale  blue         ..  ..  ..  600°     Large  saws,  pit  and  hand  saws. 

Paler  blue  with  tinge  of  green  630°    Too  soft  for  steel  instruments. 

The  tempering  colour  is  sometimes  allowed  to  remain,  as  in  watch  springs,  but  is 
generally  removed  by  the  subsequent  processes  of  grinding  and  polishing.  A  blue 
colour  is  sometimes  produced  on  the  surface  of  steel  articles  by  exposing  them  to  the 
air  on  hot  sand.  By  this  operation,  a  thin  iilm  of  iron  oxide  is  formed  over  the  surface, 
which  gives  the  colour  required.  Steel  articles  are  often  varnished  in  such  a  way  as 
to  give  them  an  appearance  of  having  retained  the  tempering  colours.  The  exact  tem- 
pering heat  required  to  produce  the  same  degree  of  hardness  varies  with  diiferent  kinds 
of  steel,  and  is  arrived  at  by  experience. 

There  are  several  ways  of  heating  steel  articles  both  for  hardening  and  tempering. 
They  may  be  heated  in  a  hollow  or  in  an  open  fire,  exposed  upon  a  hot  plate,  or  in  a 
dish  with  charcoal  in  an  oven,  or  upon  a  gas  stove.  Small  articles  may  be  heated  by 
being  placed  within  a  nick  in  a  red-hot  bar.  K  there  is  a  large  number  of  articles,  and 
a,  uniform  heat  of  high  degree  is  required,  they  may  be  plunged  into  molten  metal  alloys, 
or  oil  raised  to  the  temperature  required. 

In  hardening  steel,  care  must  bo  taken  not  to  overheat  the  metal  before  dipping.  In 
case  of  doubt,  it  is  better  to  heat  it  at  too  low  than  too  high  a  temperature.  The  best 
kinds  require  only  a  low  red  heat.  If  cast  steel  be  overheated,  it  becomes  brittle,  and 
can  never  be  restored  to  its  original  quality.  If,  however,  the  steel  has  not  been 
thoroughly  hardened,  it  cannot  be  tempered.  The  hardness  of  the  steel  can  be  tested 
with  a  file.  The  process  of  hardening  often  causes  the  steel  to  crack.  The  expansion  of 
the  inner  particles  by  the  heat  is  suddenly  arrested  by  the  crust  formed  in  consequence  of 
tlie  cooling  of  the  outer  particles,  and  there  is  a  tendency  to  burst  the  outer  skin  thus 
formed. 

When  the  whole  bulk  of  any  article  has  to  be  tempered,  it  may  either  be  dipped  or 
allowed  to  cool  in  the  air.  It  does  not  matter  which  way  they  become  cold,  provided 
the  heat  has  not  been  too  suddenly  applied ;  for  when  the  articles  arc  removed  from  tho 
heat,  they  cannot  become  more  heated,  consequently  the  temper  cannot  become  more 
reduced.  But  those  tools  in  which  a  portion  only  is  tempered,  and  in  which  the  heat 
for  tempering  is  supplied  by  conduction  from  other  parts  of  the  tool,  must  be  cooled  in 
the  water  directly  the  cutting  part  attains  the  desired  colour,  otherwise  the  body  of  the 
tool  will  continue  to  supply  heat  and  the  cutting  part  will  become  too  soft. 

When  toughness  and  elasticity  are  required  rather  than  extreme  hardness,  oil  is  used 
instead  of  water  both  for  hardening  and  tempering,  and  the  latter  process  is  sometimes 
called  "  toughening."  The  steel  plunged  into  the  oil  does  not  cool  nearly  so  rapidly  as 
it  would  in  water.     The  oil  takes  ^up  the  heat  less  rapidly.    The  heated  particles  of  oil 


66  FOEGING   AND  FINISHING. 

cling  more  to  the  steel,  and  there  is  not  so  much  decrease  of  temperature  caused  by 
vaporisation  as  tliere  is  in  using  water.  Sometimes  the  oil  for  tempering  is  raised  to  the 
heat  suited  to  the  degree  of  hardness  required.  When  a  large  number  of  articles  have  to 
be  raised  to  the  same  temperature,  they  are  treated  in  this  way. 

Saws  are  hardened  in  oil,  or  in  a  mixture  of  oil  with  suet,  wax,  &c.  They  are  then 
heated  over  a  iire  till  the  grease  inflames.  This  is  called  being  "  blazed."  After  blazing 
the  saw  is  flattened  while  warm,  and  then  ground.  Springs  are  treated  in  somewhat 
the  same  manner,  and  small  tools  after  being  hardened  in  water  are  cooled  with  tallow, 
heated  till  the  tallow  begins  to  smoke,  and  then  quenched  in  cold  tallow. 

Annealing  or  softening  steel  is  effected  by  raising  hardened  steel  to  a  red  heat  and 
allowing  it  to  cool  gradually,  the  result  of  which  is  that  it  regains  its  original  softness. 

Case-hardening  is  a  process  by  which  the  surface  of  wrought  iron  is  turned  into  steel, 
so  that  a  hard  exterior,  to  resist  wear,  is  combined  with  the  toughness  of  the  iron  in  the 
interior.  This  is  effected  by  placing  the  article  to  be  case-hardened  in  an  iron  box  full 
of  bone-dust  or  some  other  animal  matter,  and  subjecting  it  to  a  red  heat  for  a  period 
varying  from  i  hour  to  8  hours,  according  to  the  depth  of  steel  required.  The  iron  at  the 
surface  combines  with  a  proportion  of  carbon,  and  is  turned  into  steel  to  the  dejith  of  J^ 
to  §  in.  If  the  sm-face  of  the  article  is  to  be  hardened  all  over,  it  is  quenched  in  cold 
water  upon  removal  from  the  furnace.  If  parts  are  to  remain  malleable,  it  is  allowed 
to  cool  down,  the  steeled  surface  of  those  parts  is  removed,  and  the  whole  is  then  re- 
lieated  and  quenched,  by  which  the  portions  on  which  the  steel  remains  are  hardened. 
Gun-locks,  keys,  and  other  articles  which  require  a  hard  surface,  combined  with  tough- 
ness, are  generally  case-hardened.  A  more  rapid  method  of  case-hardening  is  conducted 
as  follows  : — The  article  to  be  case-hardened  is  polished,  raised  to  a  red  heat,  sprinkled 
with  finely  powdered  prussiate  of  potash.  When  this  has  become  decomposed  and  has 
disappeared,  the  metal  is  plunged  into  cold  water  and  quenched.  The  case-hardening 
in  this  way  may  be  made  local  by  a  partial  application  of  the  jirussiate.  Malleable  cast- 
ings are  sometimes  case-hardened  in  order  that  they  may  take  a  polish. 

Many  further  details  on  hardening,  tempering,  softening,  and  annealing  steel  will  be 
foiuid  in  WoRKHOP  Receipts,  Third  Series,  pp.  25G-295. 

Examples  of  Smiths'  Work. — It  will  be  instructive  to  conclude  this  section  with  detailed 
descriptions  of  the  operations  entailed  in  a  few  of  the  more  common  kinds  of  work  per- 
formed by  smiths. 

Keys. — For  forging  small  round  short  rods,  or  keys,  no  tools  are  required  except  the 
ordinary  fire  irons  and  the  hand-hammer,  tongs,  and  anvil  chisel,  in  the  anvil,  shown  by 
Figs.  68  to  70.  The  pin  should  be  forged  to  the  proper  diameter,  and  also  the  ragged 
piece  cut  off  the  small  end  by  means  of  the  anvil  chisel,  shown  by  Fig.  70,  while  the 
work  is  still  attached  to  the  rod  of  steel  from  which  it  is  made.  After  having  cut  and 
rounded  the  small  end,  it  is  proper  to  cut  the  key  from  the  rod  of  steel,  allowing  a  short 
piece  to  be  drawn  down  to  make  the  holder,  by  which  to  hold  it  in  the  lathe.  This 
holder  is  drawn  down  by  the  fuller,  and  afterwards  by  the  hammer.  The  fuller  is  first 
applied  to  the  spot  that  marks  the  required  length  of  key  ;  the  fuller  is  then  driven  in 
by  the  hammerman  to  the  required  diameter  of  the  holder,  the  bottom  fuller  being  in 
the  square  hole  of  the  anvil  during  the  hammering  process,  and  the  work  between  the  top 
and  bottom  fullers.  During  the  hammering,  the  forger  rotates  the  key,  in  order  to  make 
the  gap  of  equal  or  uniform  depth  ;  the  lump  which  remains  is  then  drawn  down  by  the 
hammers,  or  by  the  hand  hammer  only,  if  a  small  pin  is  being  made.  -If  the  pin  is 
very  small,  it  is  more  convenient  to  draw  down  the  small  lump  by  means  of  the  set 
hammer  and  the  hammerman.  The  set  hammer  is  shown  in  Fig.  74 ;  and  the  top  and 
bottom  fullers  by  Fig.  75.  The  double  or  alternate  hammering  by  forger  and  hammer- 
man should  at  first  be  gently  done,  to  avoid  danger  to  the  arm  through  not  holding  the 
work  level  on  the  anvil.  The  hammerman  should  first  begin,  and  strike  at  the  rate  of 
one  blow  a  second ;  after  a  few  blows  the  smith  begins,  and  both  hammer  the  work  at 


Forging  and  Finishing. 


67 


times,  and  other  times  the  anvil.     Figs.  71,  72,  show  the  top  and  bottom   rounding 
tools,  for  rounding  large  keys.     Large  keys  may  be  made  without  rounding  tools  by 
roimding  the  work  with  a  hand  hammer,  and  cutting  off  the  pin  by  the  anvil  cliisel 
instead  of  the  rod  chisel,  Fig.  73.     The  rod  chisel  is  so  named  because  the  handle  by 


68, 


^ 


69. 


71. 


74. 


75. 


^^^ 


CD 

ZA 


ld: 


which  the  chisel  is  held  is  an  ash  rod  or  stick,  see  Fig.  71.  A  rod  chisel  is  thin  for 
cutting  hot  iron,  and  thick  for  cutting  cold  iron.  Fig.  70  represents  the  anvil  chisel  in 
the  square  hole  of  the  anvil.  By  placing  the  steel  while  at  a  yellow  heat  upon  the  edge 
of  the  chisel,  a  small  key  can  be  easily  cut  off  by  a  few  blows  of  a  hammer  upon  the  top 
of  the  work. 

To  forge  a  key  with  a  head  involves  more  labour  than  making  a  straight  one.  There 
are  3  principal  modes  of  proceeding,  which  include  drawing  down  with  the  fuller  and 
hammer  ;  upsetting  one  end  of  the  iron  or  steel ;  and  doubling  one  end  of  a  bar  to  form 
the  head.  For  proceeding  h^  drawing  down,  a  rod  or  bar  of  steel  is  required,  whose 
diameter  is  equal  to  the  thickness  of  the  head  required ;  consequently,  large  keys  should 
not  be  made  by  drawing  down  imless  steam  hammers  can  be  used.  Small. keys  should 
be  drawn  to  size  while  attached  to  the  bar  from  which  they  are  made ;  the  di-awing  is 
commenced  by  the  fuller  and  set  hammer.  Instead  of  placing  the  work  upon  the 
bottom  fuller  in  the  anvil,  as  shown  for  forging  a  key  without  a  head,  the  steel  is  placed 
upon  the  face  of  the  anvil,  and  the  top  fuller  only  is  used,  if  the  key  required  is  large 
enough  to  need  much  hammering;  but  a  very  small  key  can  be  drawn  down  by 
dispensing  with  the  top  fuller  and  placing  the  bottom  fuller  in  the  hole,  and  placing  the 
work  upon  the  top,  and  then  striking  on  one  side  only,  instead  of  rotating  the  bar  or  rod 
by  the  hand.    By  holding  the  bar  or  rod  in  one  position,  the  head  is  formed  upon  the 

F  2 


68 


Forging  and  Finishing. 


Tincler-side  of  the  bar;  and  by  turning  the  work  upside  down,  and  drawin;^  dovm  the 
lump,  the  stem  is  produced.  The  upsetting  of  iron  generally  should  be  done  at  the 
welding  heat ;  the  upsetting  of  steel  at  the  yellow  heat,  except  in  some  kinds  of  good 
steel,  that  will  allow  the  welding  heat.  And  both  iron  and  steel  require  cooling  at  the 
extremity,  to  prevent  the  hammer  spreading  the  end  without  upsetting  the  portion  next 
to  it.  If  the  head  of  the  key  is  to  be  large,  several  heats  and  coolings  must  take  place, 
■which  render  the  process  only  applicable  to  small  work.  A  small  bar  can  be  easily 
upset  by  heating  to  a  white  heat  or  welding  heat,  and  cooling  a  quarter  of  an  inch  of  the 
end ;  then  immediately  put  the  bar  to  the  ground  with  the  hot  portion  upwards,  the 
bar  leaning  against  the  anvil,  and  held  by  the  tongs  (Fig.  7(j).  The  end  is  then 
upset,  and  the  extremity  cooled  again  after  being  heated  for  another  upsetting,  and  so 
on  until  the  required  diameter  is  attained.  When  a  number  of  bars  are  to  be  upset  in 
this  manner,  it  is  necessary  to  provide  an  iron  box,  into  which  to  place  the  ends  of  the 
bars,  instead  of  upon  the  soft  ground  or  wood  flooring,  injury  to  the  floor  being  thereby 
prevented.  "NVhen  the  key-head  is  sufficiently  upset,  the  fuller  and  set  hammer  arc 
necessary  to  make  a  proper  shoulder ;  the  stem  is  then  drawn  four-sided  and  rounded  by 

the  A  top  and  bottom  tools.    If  the  bar  from  which  the  key  is  being  made  is  not  large 

enough  to  allow  being  made  four-sided,  eight  sides  should  be  formed,  which  will  tend 
to  close  the  grain  and  make  a  good  key. 

The  third  method  of  making  keys  with  heads  is  the  quickest  of  the  three,  particu- 
larly for  making  keys  by  the  steam  hammer.  By  its  powerful  aid  we  are  able  to  use  a 
bar  of  iron  an  inch  larger  than  the  required  stem,  because  it  is  necessary  to  have 
sufficient  metal  in  order  to  allow  hammering  enough  to  make  it  close  and  hard,  and  also 
welding,  if  seamy.  If  the  bar  from  which  it  is  to  be  made  is  too  large  to  be  easily 
handled  without  the  crane,  the  piece  is  cut  from  the  bar  at  the  first  heat.  But  if  the 
bar  id  small,  it  can  be  held  up  at  any  required  height  by  the  prop,  shown  in  Fig.  77. 


16. 


While  thus  supported,  the  piece  to  be  doubled  to  make  the  head  is  cut  three-quarters  of 
the  distance  through  the  iron,  at  a  proper  space  from  the  extremity.  The  piece  is 
then  bent  in  the  direction  tending  to  break  it  off:  the  uncut  portion  being  of  sufficient 
thickness  to  prevent  it  breaking,  will  allow  the  two  to  be  placed  together  and  welded  in 
that  relation.  A  hole  may  also  be  punched  through  the  two,  while  at  a  welding  heat, 
as  shown  by  Fig.  78.  The  hole  admits  a  pin  or  rivet  of  iron,  which  is  driven  into  the 
opening,  and  the  three  welded  together.  This  plan  is  resorted  to  for  producing  a  strong 
head  to  the  key  without  much  welding ;  but  for  ordinary  purposes  it  is  much  safer  to 
weld  the  iron  when  doubled,  without  any  rivet,  if  a  sufficient  number  of  heavy  blows  can 
be  administered.  At  the  time  the  head  is  welded,  the  shoulder  should  be  tolerably 
squared  by  the  set  hammer ;  and  the  part  next  to  the  shoulder  is  theu  fullered  to  about 


Forging  and  Finishing.  69 

tbrco-qiiftrtcrs  of  the  distance  to  the  diameter  of  stem  required.  In  large  'work  the  fnller 
used  for  this  purpose  should  bo  broad,  as  iu  Fig.  79.  After  the  head  is  ■welded,  and 
the  portion  next  to  it  drawn  down  by  the  fuller,  the  piece  of  •work  is  cut  from  the  bar  or 
rod,  and  tlie  head  is  fixed  in  a  pair  of  tongs  similar  to  Fig.  80.  Such  tongs  are  useful 
for  very  small  •work,  and  are  made  of  large  size  for  heavy  work.     Tongs  of  this  character 


79. 


78. 


80. 


^. 


:f=UJ n 


nrc  suited  to  both  angular  and  circular  work.  They  will  grip  either  the  head  or  the 
Bteui,  as  shown  in  the  figure.  "While  hold  by  the  tongs  tlie  thick  lump  of  the  stem  that 
remains  is  welded,  if  necessary.  Next  draw  the  stem  to  its  proper  shape,  and  trim  the 
head  to  whatever  shape  is  required. 

Bolts. — Bolts  are  made  iu  such  immense  numbers,  that  a  variety  of  machinery  exists 
for  producing  small  bolts  by  compression  of  the  irou  while  hot  into  dies.  But  the 
machinery  is  not  yet  adapted  to  forge  good  bolts  of  large  size,  such  as  are  daily  required 
for  general  engine-making.  Good  bolts  of  large  diameters  can  now  be  made  by  steam 
hammers  at  a  quick  rate ;  and  small  bolts  of  good  quality  are  made  iu  an  economical  and 
expeditious  manner  by  means  of  instruments  named  bolt  headers.  There  is  a  variety  of 
these  touls  iu  use,  and  some  are  valuable  to  small  manufacturers  because  of  being  easily 
made,  and  incurring  but  little  expense.  The  use  of  a  bolt  header  consists  in  upsetting 
i  portion  of  a  straight  piece  of  iron  to  form  the  bolt  head,  instead  of  drawing  down  or 
reduiing  a  larger  piece  to  form  the  bolt  stem,  which  is  a  much  longer  process  ;  conse- 
quently, the  bolt  header  is  valuable  iu  proportion  to  its  capability  of  upsetting  bolt  heads 
of  various  sizes  for  bolts  of  different  diameters  and  lengths.  The  simplest  kind  of 
heading  tool  is  held  upon  the  anvil  by  the  left  hand  of  the  smith,  while  the  piece  to  be 
formed  into  a  head  is  hammered  into  a  recess  in  the  tool,  the  shape  of  the  intended 
head.  Three  or  four  recesses  may  be  drilled  into  the  same  tool,  to  admit  three  or  four 
sizes  of  bolt  heads.  Such  a  tool  is  represented  by  Fig.  SI,  and  is  made  either 
?ntirely  of  steel,  or  with  a  steel  face,  iu  which  are  bored  the  recesses  of  different  shapes 
ind  sizes. 

The  pieces  of  iron  to  be  formed  into  bolts  are  named  bolt  pieces,  When  these  pieces 
ire  of  small  diameter  or  thickness,  they  are  cut  to  a  proper  length  while  cold  by  moans 
3f  a  concave  anvil  chisel  and  stop,  or  by  a  large  she;u-iug  machine.  One  end  of  each 
piece  is  then  slightly  tapered  while  cold  by  the  hand-hammer,  Fig.  6S,  or  a  top  tool, 
rhis  short  bevel  or  taper  portion  allows  the  bolt  to  be  driven  in  aud  out  of  the  heading 
tool  several  times  without  making  sutficielit  ragged  edge  to  stop  the  bolt  in  the  hole 
svhile  being  driven  out.  Those  ends  that  are  not  bevelled  are  then  heated  to  about 
n-elding  heat,  and  upset  upon  the  anvil  or  upon  a  cast-iron  block,  on,  or  level  with,  the 
jround.  Tliis  upsetting  is  continued  until  the  smaller  parts  or  stems  will  remain  at  a 
proper  distance  through  the  tool ;  after  which,  each  head  is  shaped  by  being  hammered 
into  the  recess.  During  the  shaping  [iroc.  ss,  the  stem  of  (he  bolt  protrudes  through  the 
square  hole  in  the  auvD,  as  iudic;ited  by  Fig,  SI, 


70  FOEGING   AND   FINISHING. 

But  when  a  largo  number  of  small  bolts  are  required  in  a  sbort  tinw,  a  larger  kind 
of  heading  tool  is  made  use  of,  which  is  named  bolt  header.  One  of  these,  Fig.  82,  is 
a  jointed  bolt  header.  The  actual  height  of  these  headers  depends  upon  the  lengths  of 
bolts  to  be  made,  because  the  pieces  of  which  the  bolts  are  formed  are  cut  of  a  suitable 
length  to  make  the  bolts  the  proper  length  after  t-lie  heads  are  upset;  consequently, 
bolt  headers  are  made  2  or  3  ft.  in  height,  that  they  may  be  generally  useful.  The 
header  rciDreseuted  by  Fig.  82  contains  a  movable 
"block   B,   upon  which  rests  one  end  of  a  bolt  81- 

piece  to  be  upset ;  it  is  therefore  necessary  to  raise 
or  lower  the  block  to  suit  various  lengths  of  bolts. 
All  bolts,  large  and  small,  that  are  to  be  turned 
in  a  lathe  require  tlie  two  extremities  to  be  at 
right  angles  to  the  length  of  the  bolt,  to^  avoid 
waste  of  time  in  centring  previous  to  the  turning 
process ;  and  counectiug-rod  bolts  and  main-shaft 

bolts  require  softening,  which  makes  them  less  liable  to  break  in  a  sudden  manner; 
and  it  is  important  to  remember  that  hammering  a  bolt  while  cold  will  make  it  brittle 
and  unsafe,  although  the  bolt  may  contain  more  iron  than  would  be  suiBcient  if  the 
bolt  were  soft.  Great  solidity  in  a  bolt  is  only  necessary  in  that  portion  of  it  which  is 
to  be  formed  into  a  screw.  The  bolt  is  less  liable  to  break  if  all  the  other  parts  are 
fibrous,  and  the  lengths  of  the  fibres  are  parallel  to  the  bolt's  length.  But  in  the  screw, 
more  solidity  is  necessary,  to  prevent  breaking  off  while  the  bolt  is  being  screwed,  or 
while  in  use.  However  good  the  iron  may  be,  the  bolt  is  useless  if  the  screw  is 
unsound  ;  and  it  is  well  to  apply  a  pair  of  angular-gap  tools,  Fig.  88,  to  the  bolt  end 
while  at  welding  heat.  Bolts  of  all  kinds,  large  and  small,  are  injured  by  the  iron 
being  overheated,  which  makes  it  rotten  and  hard,  and  renders  it  necessary  to  cut  off 
the  burnt  portion,  if  the  bolt  is  large  enough  ;  if  not,  a  new  one  should  be  made  in 
l^lace  of  the  burnt  one. 

Long  bolts  that  require  the  lathe  process  are  carefully  straightened.  This  is 
convenient] y^efiected  by  means  of  a  strong  lathe,  which  is  placed  in  the  smithy  for  the 
purpose.  Long  bolts  are  also  straightened  in  the  smithy  by  means  of  a  long  straight- 
edge, which  is  applied  to  tliebolt  stem  to  indicate  the  hollow  or  concave  side  of  the  stem. 
This  concave  side  is  that  which  is  placed  next  to  the  anvil  top,  and  the  upper  side  of  the 
bolt  is  then  driven  down  by  applying  a  curved  top  tool  and  striking  with  a  sledge 
hammer.  This  mode  is  only  available  wilh  bolts  not  exceeding  2  or  3  in.  diameter  and 
of  length  convenient  for  the  anvil,  because  in  some  cases  bolts  require  straightening  or 
rectifying  in  two  or  more  j^laces  along  the  stems.  If  a  bolt  6  ft.  in  length  is  bent  1  ft. 
from  one  end,  the  bent  portion  is  placed  upon  an  anvil,  while  the  longer  portion  is 
supported  by  a  crane,  and  a  top  tool  is  api^lied  to  the  convex  part.  The  raising  of  the 
bolt  end  to  any  required  height  is  eff"ected  by  rotating  a  screw  which  raises  a  pulley,  upon 
which  is  an  endless  chain  ;  the  work  being  supported  by  the  chain,  both  chain  and  work 
are  raised  at  one  time.  It  is  necessary  to  adjust  the  work  to  the  inoper  height  while 
being  straightened;  if  not,  the  hammering  will  produce  but  little  effect.  The  amount 
of  straightening  necessary  depends  upon  the  diameters  to  which  the  bolts  are  forged, 
and  also  upon  their  near  approach  to  parallelism.  A  small  bolt  not  exceeding  Ih  in.  in 
diameter  need  not  be  forged  more  than  a  tenth  of  an  incli  larger  than  the  finished 
diameter;  a  bolt  about  2  in.  diameter,  only  an  eighth  larger;  and  for  bolts  4  or  5  in.  in 
diameter  and  4  or  5  ft.  in  length,  a  quarter  of  an  inch  for  turning  is  sufiicient,  if  the  bolts 
are  properly  straightened  and  in  tolerable  shape.  This  straightening  and  shaping  of  an 
ordinary  bolt  is  easily  accomplished  while  hot,  by  the  method  just  mentioned;  other 
straightening  processes,  for  work  of  more  complicated  character,  will  be  given  as  we 
proceed.  After  tne  bolts  are  made  sufficiently  straight  by  a  top  tool,  the  softening  is 
effected  by  a  treatment  similar  to  that  adopted  for  softening  steel,  which  consists  in 


Forging  and  Finishing.  •        71 

heating  the  bolts  to  redness  and  burying  them  in  coke  or  cinders  till  cold.  A  little  care 
is  necessary  while  heating  the  bolts  to  prevent  them  being  bent  by  the  blast.  To  avoid 
this  result,  the  blast  is  gently  administered  and  the  bolt  frequently  rotated  and  moved 
about  in  the  fire. 

Nuts. — The  simplest  method  of  making  small  nuts  is  by  punching  with  a  small  punch 
that  is  held  in  the  left  hand ;  this  punch  is  driven  through  a  bar  near  one  end  of  it, 
■which  is  placed  upon  a  bolster  on  the  anvil,  while  the  other  end  of  the  bar  is  supported 
6y  a  screw-prop.  This  mode  is  adapted  to  a  small  maker  whose  means  may  be  very 
limited.  By  supporting  the  bar  or  nuts  in  this  manner,  it  is  jiossible  for  a  smith  to  work 
without  a  hammerman.  A  bar  of  soft  iron  is  provided,  and  the  quantity  of  iron  that  is 
required  for  each  nut  is  marked  along  the  bar  by  means  of  a  pencil,  and  a  chisel  is  driven 
into  the  bar  at  the  pencil  marks  while  the  bar  is  cold.  A  punch  is  next  driven  tiirough 
while  the  iron  is  at  a  white  heat.  Each  nut  is  then  cut  from  the  bar  by  an  anvil  chisel, 
and  afterwards  finished  separately  while  on  a  nut  mandrel.  The  bar  on  the  bolster  is 
shown  by  Fig.  86. 

A  more  economical  method  is  by  punching  with  a  rod  punch,  which  is  driven  through 
by  a  sledge  hammer.  By  this  means  several  nuts  are  punched  at  one  heating  of  the 
bar,  and  also  cut  from  the  bar  at  the  same  heat.  A  good  durable  nut  is  that  in  which 
the  hole  is  made  at  right  angles  to  the  layers  or  plates  of  which  the  nut  is  composed. 
Some  kinds  of  good  nut  iron  are  condemned  because  of  these  plates,  which  separate 
when  a  punch  is  driven  between  them  instead  of  through  them.  By  punching  through 
the  plates  at  right  angles  to  the  faces  of  the  intended  nuts,  the  iron  is  not  opened  or 
separated,  and  scarfing  is  avoided.  Nuts  that  have  a  scarf  end  in  the  hole  require 
boring,  that  the  hole  may  be  rendered  fit  for  screwing ;  but  nuts  that  are  properly  punched 
may  be  finished  on  a  nut  mandrel  to  a  suitable  diameter  for  the  screw  required.  Nuts 
for  bolts  not  exceeding  2J  or  3  in.  diameter  can  be  forged  with  the  openings  or  holes  of 
proper  diameter  for  screwing  by  a  tap.  The  precise  diameter  is  necessary  in  such 
cases,  and  is  attained  by  the  smith  finishing  each  nut  upon  a  nut  mandrel  of  steel, 
which  is  carefully  turned  to  its  shape  and  diameter  by  a  lathe.  The  mandrel  is  tapered 
and  curved  at  the  end,  to  allow  the  nut  to  fall  easily  from  the  mandrel  while  being 
driven  off.  Such  nut  mandrels  become  smaller  by  use,  and  it  is  well  to  keep  a  standard 
gauge  of  some  kind  by  which  to  measure  the  nuts  after  being  forged.  The  best  kind 
of  nut  mandrel  is  made  of  one  piece  of  steel,  instead  of  welding  a  collar  of  steel  to  a 
bar  of  iron,  which  is  sometimes  done. 

One  punch  and  one  nut  mandrel  are  sufficient  for  nuts  of  small  dimensions,  but  large 
ones  require  drifting  after  being  punched  and  previous  to  being  placed  upon  a  nut 
mandrel.  The  drifting  is  continued  until  the  hole  is  of  the  same  diameter  as 
the  mandrel  upon  which  the  nut  is  to  be  finished.  The  nut  is  then  placed 
on,  and  the  hole  is  adjusted  to  the  mandrel  without  driving  the  mandrel  into 
the*.nut,  which  would  involve  a  small  'amount  of  wear  and  tear  that  may  be 
avoided.  A  good  steel  nut  mandrel,  with  careful  usage,  will  continue  serviceable, 
without  repair,  for  several  thousands  of  nuts.  The  holes  of  all  nuts  require  to 
be  at  right  angles  to  the  two  sides  named  faces ;  one  of  these  faces  is  brought 
into  contact  and  bears  upon  the  work  while  the  nut  is  being  fixed  ;  consequently,  it  is 
necessary  to  devote  considerable  attention  to  the  forging,  that  the  turning  and 
shaping  processes  may  be  as  much  as  possible  facilitated.  If  the  two  faces  of  the  nut 
are  tolerably  near  to  a  right  angle  with  the  hole,  and  the  other  sides  of  the  nut  parallel 
to  the  hole,  the  nut  may  be  forged  much  nearer  to  the  finished  dimensions  than  if  it 
were  roughly  made  or  malformed. 

To  rectify  a  nut  whose  faces  are  not  perpendicular  to  the  opening,  the  two  prominent 
corners  or  angles  are  placed  upon  an  anvil  to  receive  the  hammer,  as  indicated  in 
Fig.  87.  By  placing  a  nut  while  at  a  yellow  heat  in  this  position,  the  two  corners  are 
changed  to  two  flats,  and  the  faces  become  at  the  same  time  perpendicular  to  tho 


72 


Forging  and  Finishing. 


opening ;  the  nut  is  then  reduced  to  the  dimensions  desired.  If  the  nut  is  too  long, 
and  the  sides  of  it  are  parallel  to  the  opening,  the  better  plan  is  to  cut  prominences 
from  the  two  faces  by  means  of  a  trimming  chisel,  Fig.  91,  instead  of  rectifying  the  nut 
by  hammering.  Cutting  off  scrap  pieces  while  hot  with  a  properly  shaped  chisel  of 
this  kind  is  a  much  quicker  process  than  cutting  off  in  a  lathe. 

Small  connecting  bolts,  not  more  than  2  or  3  inches  in  diameter,  are  made  in  an 
economical  manner  by  drawing  down  the  stems  by  a  steam  hammer.  Those  who  have 
not  a  steam  hammer  will  find-  it  convenient  to  make  a  collar  to  be  welded  on  a 
stem,  in  order  to  form  a  head,  as  shown  by  Fig.  83.    After  being  welded  the  head 


83. 


84. 


may  be  made  circular  or  hexagonal,  as  required.  The  tool  for  shaping  hexagonal  heads 
is  indicated  by  Fig.  85.  Such  an  apparatus  may  be  adapted  to  a  number  of  different 
sizes  by  fixing  the  sliding  part  of  the  tool  at  any  required  place  along  the  top  of 
the  block,  in  order  to  shape  heads  of  several  different  diameters.  The  movable  or 
sliding  block  is  denoted  in  the  figure  by  S. 

Tongs. — Fig.  88  shows  a  curved-gap  tongs.  Fig.  89  a  bar  tongs,  and  Fig.  90  a 
side-grip  tongs.  Other  forms  are  illustrated  in  Figs.  92  to  99.  To  forge  and  put  together 
a  pair  of  flat  bitted  tongs  (Fig.  93),  of  the  most  usual  pattern,  select  a  bar  of  good  1  in. 


88. 


89. 


^:^_F 


91. 


square  iron  ;  lay  about  3  in.  on  the  inside  edge  of  the  anvil  (Fig.  100)  and  "  take  down  '* 
the  thickness  to  i  in.,  at  the  same  time  "  drawing  "  it  edgeways  to  maintain  the  widtli 
at  1  in. ;  this  is  done  rapidly,  so  as  to  have  heat  enough  in  the  bar  to  proceed  with, 
the  next  step,  which  consists  in  turning  it  at  right  angles,  and  hanging  the  "  bit,"  or 
part  just  taken  down,  over  the  front  edge  of  the  anvil  (Fig.  101)  and  flattening  the 
bar  just  behind  it.  The  third  step  is  performed  by  placing  the  work  about  3  in. 
farther  forward  on  the  anvil,  and  again  turning  at  right  angles  (Fig.  102),  slightly 
raising  the  back  end,  and  striking  the  iron  fairly  over  the  front  edge  of  the  anvil,  alter- 
nating the  blows  by  turning  and  returning  the  bar.     Cut  off  the  "  bit  "  3or  4  in.  behind 


Forging  and  Finishin'g, 


73 


the  part  last  treated  (Fig.  103).     Prepare  a  second  bit  in  exactly  the  same  manner, 
and  scarf  down  one  end  of  each.     For  the  liandles  or  "  reins,"  choose  a  piece  of  J-in! 


92, 


96. 


93. 


99. 


100. 


102. 


103.' 


rod,  upset  one  end,  scarf  it,  and  weld  it  to 
one  of  the  bits.  Serve  the  other  bit  the  same. 
Punch  a  -l-in.  hole  through  each,  and  connect 
them  by  riveting.  Keheat  the  finished  tongs 
and  dress  them  parallel;  then  cool  by  im- 
mersion and  constant  motion  in  cold  water. 
The  other  forms  are  made  in  a  similar 
manner,    dressing    the    bits    in    each    case 


around  pieces  of  metal   of  suitable  shape 
and  size. 

Hammers. — All  hammers  for  hand  use,  whether  chipping  hammers  or  sledge  hammers 
should  be  made  entirely  of  steel.  The  practice  of  welding  steel  faces  to  iron  eye  portions 
in  order  to  avoid  using  a  larger  quantity  of  steel,  is  more  expensive  than  making  the 
entire  tool  of  one  piece  of  steel,  and  an  unsound  inferior  tool  is  made  instead  of  a  "-ood 
one.  The  steel  selected  for  hammers  is  a  tough  cast  steel,  and  may  be  termed  a  soft 
fibrous  steel  that  will  bear  hardening.  Cast  steel  which  has  been  well  wrought  with 
rolling  and  hammering  is  suitable  for  hammers,  and  but  little  forging  is  necessary  if  tho 
metal  selected  is  of  proper  size.  The  small  chipping  hammers  and  other  hammers  for 
vice  work  are  easily  made  of  round  steel,  but  the  larger  sizes,  termed  sledge  hammers, 
require  to  be  made  of  square  bar  steel.  "When  several  are  to  be  made,  a  long  piece  is 
selected,  that  each  hammer  may  be  forged  at  one  of  tho  bar's  ends,  thus  avoiding  a  great 
portion  of  the  handling  with  tongs.  While  the  work  is  attached  to  tho  bar,  it  is  punched 
and  drifted  to  shape  the  hole,  and  also  thinned  with  top  and  bottom  fullers  at  both  sides 
of  the  hole.  The  greater  part  of  the  forging  is  thus  effected  previous  to  cutting  th(> 
hammer  from  the  bar,  and  when  cut  off",  all  rugged  portions  at  the  extremities  ara 
carefully  trimmed  off  with  a  sharp  rod  chisel,  that  the  faces  of  the  work  may  bo  solid. 

A  good  hammer  is  that  which  has  a  long  hole  to  provide  a  good  bearing  for  tho 


74  Forging  and  Finishing. 

handle,  and  which  has  the  metal  around  the  hole  curved  with  punching  and  drifting, 
the  hole  being  oval,  as  in  Fig.  104,  and  tapered  at  both  ends  or  entrances  of  the  hole. 
The  entrances  of  the  hole  are  principally  tapered  at  the  two  sides  which  are  nearest  to 
the  hammer's  faces,  tlie  other   two   sides  being  nearly  parallel. 
Steel  taper  drifts  of  proper  sliape  are  therefore  driven  into  both 
ends  of  the  hole,  to  produce  the  required  form,  and  all  filing  of 
that  part  is  thus  avoided. 

The  making  of  small  sledge  hammers  is  conducted  by  forging 
each  one  at  the  end  of  a  bar,  similar  to  the  mode  for  chipping 
hammers,  but  a  sledge  hammer,  about  20  lb.  in  weight,  is  made 
either  singly,  or  of  a  piece  of  steel  which  is  only  large  enough  to  be 
made  into  two ;  the  handling  of  a  heavy  bar  is  thus  avoided.     By  referring  to  Fig.  105, 
it  may  be  seen  that  the  handle  hole  or  shaft  hole  of  a  sledge  hammer  is  comparatively 
smaller  than  that  of  a  chipping  hammer ;  this  is  to  provide  a  solid  tool  that  will  not 
quiver  or  vibrate  when  in  use,  and  is  therefore  not  liable  to  break. 

Very  little  filing  is  sufficient  to  smooth  a  hammer,  if  properly  forged,  the  shaping 
being  easily  efiected  with  fullers  and  rounding  tools ;  and  after  being  filed,  each  of  the 
two  ends  is  hardened,  but  not  afterwards  tempered.  After  hardening,  the  two  ends 
are  finished  with  grinding  on  a  grindstone.  Polishing  the  faces  of  engineers'  hammers 
is  not  necessary. 

Through  the  handle  hole  of  a  hammer  being  tapered  at  both  ends,  the  shaft  end  is 
made  to  resemble  a  rivet  which  is  thickest  at  the  two  ends,  one  part  of  the  shaft  being 
made  to  fit  one  mouth  of  the  hole  witli  filing  or  with  a  paring  chisel  for  wood,  and  the 
outer  end  of  the  shaft  being  made  to  fit  the  other  mouth  of  the  hole  by  spreading  the 
wood  with  a  wedge.  The  wood  for  the  shaft  is  ash,  and  is  fitted  while  dry,  so  that  the 
handle  requires  hammering  to  force  its  end  into  the  hole,  and  when  the  hammering  has 
made  the  taper  shoulder  of  the  shaft  end  bear  tight  against  the  taper  mouth  of  the  hole, 
the  driving  ceases,  and  the  superfluous  wood  extending  beyond  the  wedge  end  of  the 
hole  is  cut  off,  and  the  wedge  hammered  into  its  place.  This  wedge  is  of  iron,  and  has 
an  angle  of  about  5°  or  6°;  consequently,  the  mouth  of  the  hole  should  have  the  same 
angle,  to  cause  the  wood  to  fill  the  hole  when  a  wedge  is  driven  in.  The  principal 
taper  of  the  wedge  is  in  its  thickness,  its  width  being  nearly  parallel,  to  make  it  hold 
tight  to  the  wood.  When  it  is  to  be  put  in,  it  is  placed  so  that  its  width  shall  be  parallel 
with  the  parallel  sides  of  the  hole,  the  taper  part  will  then  spread  the  wood  in  the  proper 
direction.  An  additional  means  of  tightening  tlie  wedge  consists  in  making  a  few  barbs 
upon  the  edges,  and  also  cleaning  and  chalking  it  when  it  is  to  be  hammered  into  the 
•wood. 

In  order  to  produce  a  large  number  of  hammers  of  the  same  shape  and  dimensions, 
each  one  should  be  shaped  while  between  a  couple  of  top  and  bottom  springy  shnpers. 
This  shaping  is  effected  near  the  conclusion  of  the  forging,  and  the  hammer  being 
shaped,  is  held  with  a  long  handle  drift,  whose  point  extends  a  few  inches"  tlirough  the 
hammer,  and  also  beyond  the  shapers,  the  length  of  the  hammer  being  at  right  angles 
to  the  length  of  the  drift.  After  such  shaping,  the  mouths  of  the  hole  may  be  tapered 
with  a  drift  or  with  filing ;  to  avoid  filing,  a  short  taper  drift  is  used  for  tapering  the 
mouths  of  the  hole,  and  the  long  handle  drift  for  holding  the  hammer  in  the  shapers  is 
provided  with  a  taper  shoulder,  to  fit  the  taper  mouths  of  the  hole ;  and  when  a  hammer 
is  to  be  put  between  the  shapers,  this  drift  is  hammered  tight  into  the  hole  until  the 
taper  shoulder  of  the  drift  bears  on  the  taper  mouth  of  the  hammer. 

Chisels. — Cliipping  chisels  for  engineers  seldom  remain  long  in  use,  through  the 
continual  hammering  and  consequent  vibration  to  which  they  are  subjected  for  cutting 
metals,  and  because  they  are  made  of  a  granular  tool  steel  which  is  too  solid  for  chisels, 
and  always  breaks  unless  the  cutting  part  of  the  chisel  is  too  thick  to  possess  good 
cutting  properties.    Every  sort  of  steel  which  has  been  cast,  but  not  afterwards  made 


Forging  and  Finishing.  75 

fibrous  with  hammering,  should  bo  rejected,  and  pure  iron  bars,  Wi-at  were  carbonized 
with  charcoal  without;  being  afterwards  cast,  should  bo  selected,  the  precise  quality  of  any 
cue  piece  in  all  cases  depending  on  the  quality  of  tho  iron  at  the  time  of  carbonization. 

It  is  not  possible  for  the  tool  maker  to  know  how  or  of  what;  materials  his  steel  was 
made,  but  he  is  able  to  ascertain  the  quality  of  any  piece  by  testing  it,  whicli  should 
always  be  done  previous  to  making  a  large  number  of  one  bar,  or  of  one  sort  of  steel. 
It  is  also  necessary  to  test  each  bar,  and  sometimes  both  ends  of  one  bar,  because  one 
end  may  be  much  harder  than  the  other  end,  and  the  operator  be  deceived  thereby. 

The  bar  steel  which  is  made  for  hand  chisels  is  in  the  shape  of  four-sided  bars,  each 
having  two  fiaC  sides  and  two  curved  convex  ones ;  such  a  shaiie  is  produced  with  rollino-, 
and  is  convenient  for  handling.  A  piece  of  such  a  bar,  or  a  few  inches  at  one  end  of  it, 
is  to  be  first  tested  by  heating  it  to  a  bright  red,  and  cooling  it  in  clean  cold  water  until 
the  steel  is  quite  cold ;  it  is  then  filed  with  a  saw  file,  or  some  other  smooth  file  known 
to  be  hard,  and  if  the  steel  cannot  be  cut,  its  hardening  i^roperty  is  manifested.  The 
next  test  consists  in  hardening  it  and  allowing  it  to  remain  in  the  water  till  nearly 
cold,  then  taking  it  out  and  allowing  the  heat  in  the  interior  to  expand  the  hard 
exterior ;  this  will  break  it,  if  not  fibrous  enough  to  withstand  the  trial.  A  third  test 
consists  in  making  a  grooving  chisel  of  the  steel,  and  hardening  it  ready  for  use.  This 
is  the  proper  test  for  all  chisels,  because  it  is  easily  and  quickly  performed ;  and  it  is 
advisable  to  make  the  cutting  end  rather  thinner  than  for  ordinary  chipping,  so  that  if 
it  does  not  break  nor  bend  while  thin,  it  is  reasonable  to  expect  it  would  not  break  if 
thicker. 

The  forging  of  a  chisel,  whether  a  broad  smoother  or  a  narrow  groover,  consists  in 
tapering  one  end,  and  next  cutting  off  the  cracked  extremity  which  is  produced  whenever 
steel  is  forged  thin  and  tapered.  During  the  final  reducing,  the  taper  jxirt  is  thinned 
with  a  flatter,  and  the  flattening  is  continued  till  the  end  is  below  red  heat.  Hardening 
is  next  performed  while  the  work  is  yet  warm  ;  this  consists  in  gripping  tlio  chisel  in 
tongs,  and  heating  5  or  G  in.  of  the  steel  to  redness,  then  placing  about  2  in.  of  the  taper 
part  slantways  into  water  and  moving  it  quickly  to  and  fro  till  cold ;  it  is  then  taken 
out  and  tempered,  which  is  eft'ected  with  the  heat  in  the  thick  portion  that  was  not  put 
into  the  water ;  this  heat  moves  along  to  the  hard  end  and  softens  it  while  the  operator 
rubs  off  the  thin  scale  with  a  piece  of  grindstone,  which  allows  the  colour  to  appear ; 
and  as  soon  as  a  purple  is  seen  at  the  cutting  part,  the  entire  taper  portion  is  cooled  in 
water.  This  mode  of  tempering  allows  only  about  half  an  inch  of  the  taper  part  to 
remain  hard,  all  the  remainder  being  soft ;  if  not,  the  vibration  caused  while  hammering 
would  break  the  tool  in  the  midst  of  the  taper  portion.  Some  sorts  of  steel  require 
hardening  at  a  very  dull  red,  and  tempering  until  a  quarter  of  an  inch  at  tho  end 
is  blue. 

Sharpening  chisels  ready  for  use  is  effected  on  ordinary  grindstones.  The  cutting 
edge  should  be  made  convex,  to  obtain  two  results,  one  of  which  is  rendering  the  tool 
less  liable  to  break,  and  the  other  result  is  the  greater  ease  of  cutting  while  holding  the 
tool  to  its  work.  Those  chisels  that  are  to  cut  brass  or  gun-metal  have  their  long  taper 
portions,  and  also  their  cutting  parts,  thinner  than  the 
taper  loortions  of  chisels  for  iron  and  steel,  those  for  steel  ' 

being  thickest  of  all ;  but  the  angles  of  the  taper  parts  are 
about  the  same  for  all  chisels.  When,  however,  a  small 
difference  is  made  in  such  angles,  the  smaller  angle  is  given 
to  those  for  cutting  brass  and  gim-metal.     The  angle  of  a 

hand  chisel's  long  taper  portion  is  only  about  6°,  but  that  of  the  cutting  end  is  about 
G0°.  In  Fig.  lOG  a  narrow  side  of  a  chisel  is  shown,  and  a  couple  of  lines  are  made  that 
extend  from  the  cutting  end ;  two  other  lines  are  also  shown,  which  extend  from  the 
long  taper  part,  the  difference  between  the  two  angles  being  indicated  by  such  lines. 

It  is  only  during  the  mending  of  a  chisel  that  the  proper  management  can  be  exactly 


76  Forging  and  Finishing. 

effected.  After  they  have  been  in  use,  the  workman  can  decide  whether  the  metal  he  is 
cutting  requires  the  chisels  to  be  harder  or  softer  than  they  were  when  first  hardened, 
so  that  he  instructs  the  tool  maker  to  make  them  harder,  if  necessary,  or  to  make  them 
thicker  at  the  cutting  part,  if  steel  or  hard  iron  is  being  chipped.  By  using  a  chisel 
it  is  also  discovered  whether  it  were  left  too  hard  at  its  tempering,  and  needs  different 
treatment. 

To  prevent  the  head  of  a  chisel  burring  around  the  edges  with  hammering,  and 
causing  pieces  to  fly  off,  the  head  should  be  frequently  curved  with  grinding,  at  the 
time  the  cutting  part  is  sharpened ;  and  when  a  head  is  mended  at  a  forge,  the  end 
may  be  tapered,  but  none  of  the  burr  is  to  be  hammered ;  all  these  should  be  cut  off 
with  a  small  trimmer,  or  ground  off  with  a  grindstone,  previous  to  tapering  on  the 
anvil. 

Files. — The  processes  to  which  files  are  subjected,  after  receiving  them  from  the 
file  maker,  include  hardening,  bending,  cranking  the  tangs,  and  shaping  the  tangs  to 
prevent  their  handles  falling  off. 

Kough  files  are  oftener  made  of  inferior  steel  than  smooth  ones,  and  if  the  metal  is 
not  capable  of  properly  hardening  in  ordinary  water,  salt  water  is  used;  and  if  an 
extraordinary  hardness  is  requisite,  the  file  may  be  hardened  in  mercury.  Eough  files 
are  often  softer  than  they  should  be,  to  prevent  their  teeth  breaking  off  during  use  ; 
this  should  be  remedied  by  forming  the  teeth  so  that  they  shall  be  inclined  at  a  proper 
angle  to  the  file's  broad  sides,  and  by  properly  polishing  the  sides  previous  to  forming 
the  teeth ;  smooth  teeth  are  more  durable  than  rugged  ones,  and  teeth  having  smooth 
extremities  cannot  be  produced  if  the  blank  sides  are  not  smooth.  The  cutting  sides  of 
a  file  miist  be  convex,  and  to  obtain  this  form  the  middle  of  tlie  file  is  made  thickest. 
The  convexity  of  one  side  of  a  flat  file  is  destroyed  if  the  tool  bends  much  in  hardening, 
and  if  found  to  be  thus  bent,  it  is  heated  to  dull  red  and  hammered  with  a  wood  hammer 
while  lying  across  a  wood  block  having  a  concave  face;  this  hammering  is  equally 
administered  along  the  entire  length  to  avoid  forming  crankles,  after  which  it  is  heated 
to  redness  and  hardened.  Half-round  files  are  always  preferable  if  the  half-round  sides 
are  convex  and  the  point  very  much  tapered.  A  rough  file  which  is  made  of  soft  steel 
that  cannot  be  properly  hardened,  is  improved  by  heating  it  to  a  bright  red  and  rolling 
it  in  a  long  narrow  box  containing  powdered  prussiate  of  potash ;  the  file  is  then  held 
in  the  fire  a  few  seconds  until  the  powder  attached  is  melted,  when  the  work  is  cooled 
in  water.  The  tangs  of  files  are  not  hardened,  or,  if  hardened,  are  always  made  quite 
soft  afterwards,  to  prevent  them  breaking  while  in  use. 

In  order  to  crank  the  tang  of  a  file  without  softening  its  teeth,  it  is  necessary  to  bind 
a  couple  of  thick  pieces  of  iron  to  that  portion  which  adjoins  the  tang,  and  to  heat  the 
tang  as  quickly  as  possible  by  putting  it  through  the  hole  of  a  thick  iron  ring  which  is 
at  near  welding  heat ;  this  ring  is  narrow  enough  to  allow  the  greater  part  of  the  tang's 
length  to  extend  beyond  the  hole,  by  which  means  the  thick  portion  in  the  hole  is 
heated  to  redness  while  the  thin  end  remains  black.  When  the  proper  heat  is  thus 
obtained,  the  first  bend  to  commence  the  cranking  is  made  by  bending  the  work  while 
in  the  hole,  if  the  hole  is  small  enough ;  if  not,  the  bending  is  performed  on  the  anvil 
edge.  The  situation  of  the  first  bend  is  near  the  file's  teeth,  and  the  second  bend  nearer 
the  tang's  point  is  afterwards  easily  made,  because  it  is  not  necessary  to  heat  the  tang 
in  its  thick  part. 

File  handles  frequently  slip  off  through  the  tangs  being  too  taper :  this  is  remedied 
by  grinding  and  filing  the  tang  at  its  thickest  end,  without  heating  it  and  thinning  it  on 
an  anvil,  especially  if  the  file  is  a  good  one.  Handles  also  slip  off  through  their  holes 
being  of  a  wrong  shape,  resulting  from  using  one  handle  for  several  files.  The  proper 
mode  of  fitting  a  handle  to  a  tang  consists  in  making  a  small  round  hole  which  is  nearly 
as  deep  as  the  length  of  the  tang,  and  next  shaping  the  hole  to  the  desired  form  by 
burning  out  the  wood  with  the  tang  ;  for  this  purpose  it  is  heated  to  a  bright  red  at  the 


FORQING   AND    FINISHING.  77 

point,  and  a  dull  red  at  flie  thick  part ;  it  13  then  pushed  into  the  handle,  and  allowed 
to  remain  in  a  few  seconds,  when  it  is  pulled  out  and  tho  dust  sliaken  from  the  hole ; 
tlie  tang  is  then  again  heated  and  put  the  same  way  into  tho  hole,  to  oljtaiu  the  proper 
shape.  One  heating  of  the  tang  is  sufficient,  except  it  happens  that  the  round  holo 
■were  too  small  or  too  shallow,  when  two  or  throe  burnings  may  be  necessary.  In  order 
to  avoid  the  danger  of  softening  a  good  file,  it  is  proper  to  use  the  fang  of  an  old  fdc, 
observing  that  its  shape  is  similar  to  that  of  the  tang  to  be  fitted. 

Scrapers.— A  scraper  having  a  flat  extremity  is  easily  made  of  a  small  flat  file,  tho 
thin  taper  portion  of  tho  file  being  first  broken  off,  and  a  straight  smooth  extremity 
produced  with  grinding  on  a  grindstone.  Tho  two  broad  sides  are  ground  near  tho 
intended  cutting  edges,  to  destroy  all  convexity  in  that  part,  and  to  produce  a  slight 
concavity,  for  giving  a  cutting  projierty  to  the  edges,  these  two  concave  sides  being 
afterwards  polished  with  flour-emery  cloth.  The  flat  extremity  requires  to  be  slightly 
curved  and  convex,  and  is  ground  until  about  a  sixteenth  of  an  inch  prominent  in  the 
middle.  After  such  a  scraper  has  been  properly  made,  tlie  several  grindings  for 
sharpening  are  entirely  performed  upon  the  flat  extremity,  so  named,  the  broad  sides 
not  being  ground,  but  merely  rubbed  on  an  oilstone.  An  oilstone  is  also  required 
to  smoothly  polish  the  cutting  part  every  time  the  tool  is  sharpened. 

Three-cornered  scrapers  are  much  used,  and  are  made  of  triangular  files  of  various 
sizes  ;  the  points  of  these  are  ground  on  a  grindstone  until  the  three  intended  cutting 
edges  are  regularly  curved  and  convex ;  and  the  tool  is  finally  polished  on  an  oilstone. 
Scrapers  having  broad  thin  ends  for  scraping  sides  of  holes,  concave  surfaces,  brasses, 
shells  of  steam-cocks,  and  similar  work,  require  a  concave  side,  that  may  be  termed 
the  bottom.  This  side  or  surface  is  that  which  bears  on  the  surface  being  scraped, 
and,  through  being  concave,  the  tool  has  a  superior  cutting  property,  and  is  also  easily 
moved  to  and  fro  by  the  operator  without  being  liable  to  rock  or  cant  while  on  the 
work. 

A  mode  of  making  a  scraper  very  light,  to  promote  an  easy  handling,  consists  in 
thinning  the  intermediate  portion,  thus  making  it  much  thinner  than  the  cutting  part. 
If  a  scraper  thus  lightened  is  not  thick  enough  to  permit  its  being  firmly  held  by  the 
workman,  the  thin  portion  is  covered  with  a  few  layers  of  cloth,  flannel,  worsted,  felt, 
or  similar  substance,  to  enlarge  the  mid-part  of  the  tool  to  a  convenient  thickness.  Such 
a  covering  is  also  useful  for  all  scrapers,  whether  thick  or  thin,  rectangular  or  triangular, 
if  they  are  small,  to  avoid  cramping  the  fingers. 

Scrapers  that  are  made  of  files  by  grinding  need  no  hardening ;  but  if  one  has  been 
forged  by  thinning  and  spreading  one  end  of  a  piece  of  round  steel,  the  process  of 
hardening  is  performed  after  the  tool  is  roughly  filed  to  its  shape.  For  scrapers,  no 
tempering  is  necessary. 

Drifts. — Cutting  drifts  having  teeth  on  their  sides,  similar  to  large  file  teeth,  are 
shaped  by  two  methods ;  small  ones  not  more  than  1  in.  thick  being  grooved  by  filing, 
and  large  ones  that  may  be  3  or  4  in.  thick  being  grooved  with  a  planing  machine  or 
shaping  machine. 

The  steel  suitable  for  drifts  is  a  tough,  well-hammered  metal  that  has  not  been  cast, 
and  the  smaller  the  intended  tool  the  greater  is  the  need  to  select  an  elastic  fibrous 
metal  which  will  bend  after  being  hardened,  and  not  be  liable  to  crack  in  hardening 
through  being  too  solid.  Small  thin  drifts  may  be  made  of  a  hard  Swedish  iron,  and 
afterwards  jjartly  carbonized  to  steel  the  exterior.  A  drift  thus  made  will  sustain  a 
severe  bending  while  in  a  crooked  hole,  without  being  so  liable  to  break  as  if  the  entire 
tool  were  of  steel.  The  short  drifts  do  not  bend  while  being  hammered  through  a  piece 
of  work ;  they  may  therefore  bo  made  of  steel ;  but  all  long  ones  that  are  comijaratively 
thin  are  more  pliable  if  made  of  iron.  The  hammering  of  any  drift,  whether  long  or 
short,  shakes  and  tends  to  break  it,  and  it  is  advisable  to  make  each  one  as  short  as  its 
intended  work  will  permit.    Those  for  drifting  small  holes  often  require  long  huudlca, 


78  FOEGING   AND   FINISHING. 

similar  to  that  shown  in  Fig.  107 ;  such  a  handle  is  thinner  tiian  ne  portion  for  cutting, 
that  all  its  teeth  may  be  driven  through  the  work. 

Iron  drifts  are  steeled  by  being  packed  in  charcoal  in  boxes ;  the  lids  are  put  on, 
all  the  crevices  are  filled  with  loam,  and  a  thick  layer  of  loam  is  put  on  the  ledge,  which 
extends  all  round  the  mouth  for  the  convenience  of  supporting  the  loam.     After  all  the 
crevices  are  thus  filled,  to  keep  out  the  air,  the  affair  is  put 
into  a  large  clear  fire,  that  plenty  of  room  may  exist  around,  107. 

and  gradually  heat  all  sides  of  the  Ix)x  at  one  time.    A  

I^late  furnace  fire  will  afford  a  convenient  heat,  a  substitute       ^^  {'\\^\'^'\\^ 

being  a  largo  forge  fire ;  if  this  is  used,  the  blast  is  very 
gently  administered  until  the  work  is  red  hot,  when  the  blast 

is  stopped,  and  the  work  is  allowed  to  remain  at  the  same  heat  for  2  hours,  during 
which  time  the  drifts  have  absorbed  the  carbon  from  the  charcoal,  and  the  surfaces  are 
steeled.  This  being  done,  each  one  is  taken  carefully  from  the  charcoal  without  bruising 
the  edges,  and  allowed  o  cool  separately,  if  they  are  required  immediately ;  if  not,  the 
box  is  taken  from  the  firO;  he  lid  is  raised,  and  the  work  is  allowed  to  slowly  cool  while 
among  the  charcoal.  When  t  he  drifts  are  cold,  they  are  put  into  order  for  hardening. 
This  may  be  done  at  any  future  time,  and  consists  in  sharpening  the  teeth  and  polishing 
the  surfaces,  to  make  them  as  they  appeared  previous  to  being  heated,  and  when  they 
are  to  be  hardened  they  are  again  heated  and  cooled  in  water.  This  second  heating  is 
seldom  necessary  for  drifts  if  they  are  properly  finished  previous  to  steeling,  and  they 
may  be  hardened  while  hot  at  the  time  they  are  first  carbonized.  Drifts  thus  steeled 
may  be  softened  at  any  future  time  when  the  teeth  require  sharpening,  and  again 
hardened  by  merely  heating  and  dipping  into  water,  because  heating  the  tool  does  not 
liberate  the  carbon. 

This  method  of  carbonizing  is  also  adopted  for  changing  the  surfaces  of  iron  screw- 
taps  into  steel;  taps  thus  treated  are  useful  for  several  classes  of  work,  if  properly 
managed. 

Punches. — A  punch  with  a  circular  extremity,  for  making  round  holes  into  cold 
sheet  iron  and  other  metals,  is  about  G  in.  long,  and  made  of  an  old  round  file,  to  avoid 
forging.  The  file  is  first  thoroughly  softened  along  its  entire  length,  and  one  end  is 
reduced  imtil  of  a  proper  diameter  to  make  the  holes  desired ;  this  reducing  is  often 
done  with  a  grindstone,  while  the  file  is  soft,  when  forging  cannot  be  efiected,  and  the 
intended  cutting  extremity  is  ground  until  flat.  When  properly  shaped,  the  tool  is 
hardened  by  heating  to  redness  about  3  in.  of  its  length,  and  placing  about  1  in.  into 
water,  moving  it  to  and  fro  as  for  hardening  other  tools ;  as  soon  as  the  tool's  extremity 
is  cold,  it  is  taken  from  the  water  and  cleaned,  during  which  time  the  heat  slowly 
softens  the  end,  and  when  a  blue  colour  appears  at  J  or  |  in.  from  the  extremity,  the 
hard  part  of  the  punch  is  cooled,  but  the  remainder  is  allowed  to  cool  as  slowly  as 
possible,  that  it  may  be  quite  soft. 

Square  punches  and  other  angular  punches  for  hand  use  are  of  the  same  length  as 
round  ones,  and  are  made  of  properly  softened  round  and  square  files.  Punches  are  not 
merely  required  to  make  holes ;  they  are  useful  for  smoothing  and  polishing  the 
boundaries  of  various  recesses  that  cannot  be  filed,  scraped,  or  ground.  A  punch  for 
such  work  is  held  in  one  hand,  and  aj^plied  to  the  work  while  the  head  of  the  punch  is 
hammered  until  the  surface  in  contact  is  shaped.  Tools  of  this  class  have  shaping 
extremities  of  various  forms,  some  being  curved  and  convex,  others  are  concave,  some 
are  provided  with  ridges,  Imobs,  teeth,  and  otlier  protuberances,  the  extremities  of  others 
are  rectangular,  triangular,  and  oval,  having  recesses  of  several  forms.  All  such 
punches  require  a  careful  polishing,  both  previous  to  hardening  and  afterwards,  and  the 
better  the  polish  given  to  the  punch,  the  smoother  will  be  the  surface  to  be  punched. 
The  ends  of  such  tools  are  specially  tempered  after  hardening,  to  suit  their  respective 
shapes,  those  extremities  which  are  broad,  and  consequently  strong,  being  tempered  to  a 


Forging  and  Finishing. 


79 


108. 


(2 


109. 


110. 


brown,  unless  the  steel  happens  to  be  a  brittle  cast  steel,  for  which  metal  the  temper 
denoted  by  blue  is  necessary. 

Spanners.— The  proper  metal  for  spanners  generally,  is  a  soft  fibrous  Bessemer  steel  ; 
such  metal  is  produced  by  rolling  and  hammering  the  Bessemer  product  after  being 
cast,  that  the  fibrous  character  may  be  produced.  If  such  steel  is  soft  cnou"-li,  it  will 
■weld,  and  spanners  of  all  shapes  may  be  made  of  it. 

To  make  a  gap  spanner  quickly  for  immediate  use,  one  end  of  an  iron  or  steel  bar  is 
heated  to  a  bright  yellow  heat,  and  bent  until  a  hook  is  formed ;  the  work  is  next 
heated  at  the  curved  part,  and  lengthened  or  shortened  until  the  gap  is  of  a  proper 
width,  A  gap  spanner  of  this  character  is  shown  by  Fig.  108.  Another  simple  class  of 
gap  spanners  are  those  made  of  thm  bar  or  plate  steel.  A  spanner  of  this  sort  needs  no 
thinning  to  produce  the  handle,  because  the  gap  iwrtion  is  no  thicker  than  the  handle  ; 
it  is  therefore  made  by  cutting  out  witli  chisels  while 
the  plate  is  at  bright  red  heat.  Small  spanners  only 
should  be  made  by  this  mode,  because  of  their  wide 
gap  portions,  and  are  represented  by  Figs.  109 
and  110. 

Small  gap  spanners,  of  only  1  or  2  lb.  each  in 
weight,  are  easily  made  of  steel,  and  should  have 
cylindrical  handles,  usually  termed  round  handles, 
to  promote  an  easy  handling.  Large  spanners  may 
have  broad  thin  handles,  that  they  may  be  light, 
and  the  two  edges  or  narrow  sides  are  curved.  A 
gap  spanner  with  only  one  gap  end  is  made  by 
providing  a  bar  which  is  thick  enough  to  be  made 
into  the  spanner's  gap  portion  without  upsetting, 
and  thinning  the  end  of  the  bar  until  it  is  of  the 
desired  length  and  shape  for  the  spanner's  handle. 
The  gap  in  the  thick  portion  is  next  made  by  first 
punching  a  hole  at  the  place  for  the  bottom  of  the 
intended  gap,  a  round  punch  being  used  if  the 
bottom  is  to  be  curved,  and  a  6-sided  punch  or  driCt, 
if  the  bottom  is  to  be  angular.  When  the  hole  is 
made,  two  slits  are  formed  from  the  hole  to  the 
extremities,  and  the  superfluous  gap-piece  is  cut  out, 
at  which  time  the  work  is  roughly  prepared  for  an 
after  trimming.  Another  spanner  is  next  partly 
made  by  the  same  means  of  the  same  bar,  if  neces- 
sary, and  any  greater  number  that  may  be  required. 
A  spanner  in  process  of  being  made  of  such  a  piece 
is  indicated  by  Fig.  111. 

The  forging  of  a  spanner  which  is  to  have  a  gap 
at  each  end  is  effected  by  making  two  gap-pieces,  each  one  having  a  gap  of  proper  size, 
and  an  end  or  stem  of  about  half  the  entire  length  of  the  intended  simnner.  These  two 
stems  are  scarfed,  or  a  tongue-joint  is  made,  for  the  jjurpose  of  welding  them  together, 
which  produces  the  desired  spanner  having  a  gap  at  each  end.  After  being  shaped  at 
the  gap  parts,  the  spanner  is  bent,  whether  it  has  one  gup  or  two,  the  bending  being 
necessary  that  the  spanner  may  be  applied  to  the  6  sides  of  a  nut  by  moving  the  handle 
to  and  fro  in  the  shortest  possible  space.  This  bending  consists  in  heating  the  junction 
of  the  gap  part  with  its  stem,  and  bending  it  until  the  handle  or  stem  is  at  an  angle  of 
15°  with  the  gap-sides. 

The  final  shaping  of  a  gap-spanner  consists  in  trimming  the  edges  with  a  trimming 
chisel  and  curving  the  outer  surfaces.     Half-round  top  and  bottom  tools  are  employed 


112. 


o 


3) 


113. 


0 


80  Forging  and  Finishing. 

for  this  curving,  and  the  edges  of  the  gap  portions  are  shaped  while  between  such  tools, 
and  also  while  a  filler  is  iu  the  spanner's  gap.  This  filler  is  of  steel,  and  is  long  enough 
to  be  supported  on  a  couple  of  blocks,  or  across  an  opening  of  some  sort,  while  the 
spanner's  gap-part  is  held  on  the  filler  and  shaped  with  the  top  and  bottom  tools.  One 
narrow  side  of  the  filler  is  angular,  similar  to  the  bottom  of  the  gap,  and  the  thickness  is 
the  forged  width  of  the  gap  ;  consequently,  while  the  outer  surfaces  are  being  shaped  at 
the  time  the  filler  is  in  the  gap,  both  the  gap  and  the  outer  edges  of  the  gap  portion  are 
shaped  at  one  hammering. 

In  order  to  provide  good  bearings  in  the  gap  surfaces,  and  to  prevent  the  entire  gap 
portion  being  too  broad,  and  thereby  occupying  too  much  room,  the  thickness  of  a  gap 
portion  belonging  to  a  small  spanner  should  be  about  equal  to  the  height  of  the  nut 
which  is  to  be  rotated,  and  the  total  breadth  across  the  gap  part  only  about  3  times  the 
diameter  of  the  hole  in  the  nut.  Large  spanners  for  nuts  3  or  4  in.  height,  may  have  gap 
parts  which  are  two-thirds  of  the  nuts'  heights.  The  proper  shape  for  the  bottom  of  a 
spanner's  gap  is  angular,  that  it  may  fit  any  two  contiguous  sides  of  i\  6-sided  nut  or 
bolt  head.  Gaps  of  such  a  form  will  suit  hexagonal  nuts  and  square  ones.  A  gap  with 
a  ciurved  bottom  braises  the  nuts'  corners,  and  it  must  be  made  very  deep  to  prevent  the 
spanner  slipping  off  while  in  use.  By  Fig.  112  a  spanner  is  represented  whose  gap  part 
is  of  proper  shape. 

Gap  spanners  are  often  forged  of  ordinary  fibrous  wrought  iron,  and  after  they  are 
properly  finished  and  the  gap  surfaces  smoothly  filed  to  suit  the  nuts,  the  entire  gap 
portion  of  each  spanner  is  hardened  ;  this  is  performed  by  heating  it  to  a  bright  red, 
rolling  it  in  powdered  prussiate  of  potash,  and  then  cooling  it  in  clean  water.  Small 
iron  spanners,  that  are  only  G  or  8  in.  long,  are  put  into  a  box  with  bones  or  hoofs,  and 
their  entire  surfaces  are  steeled,  similar  to  the  mode  for  steeling  other  small  tools. 

Cast-iron  spanners  are  those  that  are  made  by  pouring  the  metal  into  sand  moulds 
that  are  shaped  with  wood  or  iron  patterns  resembling  the  spanners  to  be  cast.  After 
casting,  the  spanners  are  softened  by  a  long  gradual  cooling,  which  makes  the  metal 
soft,  and  prevents  the  tool  breaking  while  in  use,  although  the  metal  is  not  made  fibrous. 
Cast  steel  thus  used  is  a  preferable  metal  to  cast  iron. 

The  stems  and  handles  of  socket  spanners  are  made  of  round  iron  or  steel,  and 
separate  from  the  socket  portions.  The  socket  portion  of  the  spanner  consists  of  a 
tubular  piece  which  is  attached  to  the  stem  by  welding  its  end  in  the  socket  hole.  This 
socket  piece  may  be  an  end  of  a  thick  tube,  if  such  a  piece  can  be  obtained  with  a  hole 
of  proper  diameter.  The  socket  may  be  made  also  by  punching  a  hole  through  a  solid 
piece,  and  drifting  the  hole  to  a  proper  shape  and  size;  this  produces  a  good  socket  if 
the  metal  is  solid.  The  convenient  mode  of  making  a  socket  of  an  iron  or  soft  steel  bar 
consists  in  .curving  to  a  circular  form  one  end  of  a  bar  which  is  about  as  thick  as  the 
intended  socket,  and  welding  the  two  ends  together  by  means  of  a  sort  of  scarf  joint 
termed  a  lap  joint.  Such  a  joint  is  made  by  tapering  both  the  ends  tliat  are  to  be  welded 
together,  and  curving  the  socket  piece  until  its  hole  is  about  three-quarters  of  its 
finished  diameter,  which  allows  the  socket  to  be  stretched  with  welding  to  its  proper 
diameter.  After  a  socket  is  made  by  either  of  these  means,  its  hole  is  shaped  with  a 
steel  6-sided  drift  which  is  of  the  same  shape  and  thickness  as  the  required  socket  hole. 
One  end  of  the  socket  is  next  heated  and  upset,  to  make  it  thicker  and  larger  in  diameter 
than  the  remainder,  at  which  time  it  appears  as  in  Fig.  113,  being  then  ready  for 
welding  to  the  stem. 

The  preparation  of  the  stem  consists  in  thickening  one  end  by  upsetting,  and  shaping 
it  to  a  6-sided  form  to  fit  the  socket-hole.  A  stem  thus  shaped  is  denoted  by  Fig.  114; 
and  the  thick  part  is  made  to  fit  tight  in  the  hole,  that  it  may  be  easily  handled  and 
welded  in  that  situation.  The  length  of  the  part  which  is  in  immediate  contact  with 
the  enlarged  end  of  the  hole  is  about  half  of  tlie  socket's  length,  and  while  the 
two  are  together  a  welding  heat  is  given  them,  and  they  are  welded  with  a  couple  of 


Forging  and  Finishing,  81 

mgnlar-gap  fools  wbilo  the  socket  is  between.  During  this  vrelding,  tlie  tools  are  in 
iontact  with  only  that  part  which  contains  tlie  end  of  tlic  stem,  in  order  that  tlio  liolo 
nay  not  be  made  much  smaller  by  the  hammering.  Tliis  welding  reduces  the  thick 
)art  of  the  socket  to  the  same  diameter  as  the  thinner  part,  and  also  lengthens  the 
)earing  of  the  stem  in  the  hole. 

The  final  shaping  of  the  socket,  after  it  is  properly  attached  to  the  stem,  is  accom- 
dished  by  trimming  off  superfluous  metal  to  make  the  socket  to  a  proper  length 
nd  smoothly  finishing  the  hole  with  a  G-sided  filler.  This  filler  is  parallel  and  is 
larefully  made  so  that  it  shall  be  the  precise  thickness  and  shape  of  the  finished  hole 
leing  tapered  a  short  distance  at  the  point,  that  it  may  enter  easily  into  the  hole  wheii 
lecessary.  The  extremity  of  the  part  which  is  in  the  hole  is  smoothly  shaped  and 
urved,  for  smoothing  the  bottom  of  the  socket  hole.  This  smoothing  is  effected  by 
leatiug  that  part  of  the  socket  and  hammering  the  end  of  the  stem  while  the  filler  is  in 
he  hole  and  touches  its  bottom.  To  conveniently  hammer  the  stem,  the  filler  is  put 
Qto  the  hole,  and  the  outer  end  of  the  filler  is  then  put  to  the  floor  with  the  socket-stem 
xtending  upwards,  the  filler  resting  on  a  soft  iron  block  or  lead  block,  whose  top  ia 
3vel  with  the  floor ;  while  thus  arranged,  the  upper  end  of  the  stem  is  hammered  and 
lie  bottom  of  the  holo  is  shaped.  A  filler  of  this  class,  in  the  hole  of  a  socket  is 
Bpiesented  by  Fig.  115.  Through  such  a  filler  being  nearly  or  quite  parallel  along  a 
reat  part  of  its  length,  it  cannot 

e  released  from  any  socket  after  lu. 

eing  once  hammered  in,  without 
eating  it  and  enlarging  the  holo 
aough  to  let  out  the  filler  with 
ulling  in  a  vice,  or  similar  means.  115. 

The  handle  end  of  the  stem  for 


g  Si 


socket  spanner  is  provided  with  a  C'';|J|i»M  H  0 

Die,  if  to  be  used  with  a  separate 

iver,  or  provided  with  a  y  handle,  ue 

to  be  rotated  by  such  means ;  and 

the  spanner  has  a  bent  stem,  con- 

ituting  a  handle  which  is  at  right 

igles  to  the  length  of  the  socket, 

le  stem  is    heated   to    make    the  ii7, 

jnd  in  the  right  place,  after  all 

e  joint-making  is  completed. 

If  a  socket  spanner  is  not  to  be 
the-turned,  it  is  necessary  to  care- 
lly  reduce  the  work  to  a  proper 
lape  and  dimensions  while  on  the 

ivil;  but  if  to  be  turned,  a  proper  amount  of  metal  is  allowed,  that  the  socket  may 
)t  be  too  thin.  A  socket  spanner  is  turned  while  its  handle  end  is  supported  on  the 
andrel  pivot  of  a  lathe,  and  its  socket  part  is  supported  on  a  broad  conical  pivot,  which 
large  enough  to  bear  on  the  edges  of  the  hole's  mouth.  By  tliis  method,  the  socket 
accurately  turned  so  that  one  side  shall  be  just  as  thick  as  the  opposite  side,  and  if 
e  entire  length  of  the  socket  were  forged  parallel  to  the  drift  while  in  the  hole,  the 
itire  outer  surface  of  the  socket  when  turned  would  be  also  parallel  with  the  hole. 

A  spanner  which  has  a  boss  at  one  end  containing  a  square,  G-sided,  or  round  hole, 
forged  at  one  end  of  a  bar  which  is  nearly  as  thick  as  the  length  of  the  boss  which  is 
have  the  hole.  At  the  end  of  the  bar  a  portion  is  reduced  until  small  enough  for  the 
mdle,  and  the  thick  portion  adjoining  is  punched  with  a  taper,  square,  or  round  punch, 
id  also  drifted  while  at  welding  heat  with  taper  drifts  of  proper  shapes.  In  Fig.  IIG 
spanner  being  made  at  one  end  of  a  bar  is  shown,  and  may  be  partly  drifted  while 

o 


82  Forging  and  Finishing. 

attached  to  the  bar,  and  also  afterwards,  while  separate,  as  denoted  bj-  Fig.  117,  When 
it  is  cut  from  the  bar,  the  shaping  of  the  boss  is  completed  by  hammering  the  outside 
while  at  welding  heat,  and  by  fullers  applied  to  the  junction  of  the  boss  with  the 
handle  ;  during  both  these  processes  a  drift  is  in  the  hole  ;  a  drift  is  also  in  the  hole  of 
a  boss,  which  is  circular,  and  being  rounded  with  half-round  top  and  bottom  tools. 

The  drifts  for  enlarging  the  holes  are  very  taper,  similar  to  the  one  shown  in 
Fig.  117,  and  those  for  adjusting  holes  to  proper  diameters  are  so  nearly  parallel  that 
they  appear  parallel  to  ordinary  observation.  A  parallel  drift  is  indicated  in  Fig.  118 
and  is  tapered  at  each  end,  to  prevent  its  being  stopped  by  the  burs  made  with 
hammering  while  being  driven  into  or  out  of  a  hole. 

Several  drifts  of  various  sizes  and  shapes  are  always  kept  ready  by  the  smith,  and  by 
a  proper  use  of  the  parallel  ones  a  spanner  with  a  circular  hole  can  be  enlarged  until 
the  desired  amount  of  metal  remains  for  boring  the  boss  to  the  stated  dimensions  ;  and 
if  the  spanner  being  finished  has  a  square  or  6-sided  hole,  it  can  be  drifted  until  it  fits 
the  nuts,  bolt  heads,  spindle  end,  plug  end,  or  other  works  for  which  the  spanner  is 
made,  thus  avoiding  much  filing,  drifting  with  cutting  drifts,  and  other  lengthy 
processes. 

Wrenches. — Wrenches  for  rotating  taps,  broaches,  and  similar  tools  are  made  of  three 
portions  for  each  wrench,  one  piece  being  the  boss  which  is  to  contain  the  hole  or  holes, 
and  the  other  pieces  being  round  straight  pieces  for  the  handles,  the  three  being 
separately  made,  and  the  holes  in  the  boss-part  finished,  previous  to  welding  the  pieces 
together.  The  length  of  the'boss-part  depends  on  the  number  of  holes  to  be  in  it,  and 
after  the  length  is  ascertained,  a  piece  of  soft  steel  is  selected  which  is  large  enough  for 
the  boss,  and  long  enough  to  allow  a  stem  to  be  thinned  at  each  end  of  the  boss ; 
this  component  piece  is  first  properly  marked  while  cold,  to  denote  the  commencement 
of  each  stem,  and  next  fullered  with  top  and  bottom  fullers  to  commence  the  thinning, 
wliich  reduces  the  stems  to  a  proper  diameter.  A  boss-piece  of  this  class  is  shown 
by  Fig.  119,  which  is  to  have  only  one  square  hole.  Another  bo.ss-piece,  made  by  the 
same  means,  but  having  3  holes,  is  represented  by  Fig.  120  ;  in  this  figure  a  mouth  for 
a  tongue  joint  is  shown  at  the  end  of  each  stem,  such  a  joint  being  adopted  when 
making  large  tap  spanners.  A  tap  spanner  to  be  welded  by  means  of  scarf  joints  is 
indicated  by  Fig.  121,  in  which  the  ends  are  thickened  and  bevelled  ready  for  welding. 
When  the  handles  are  welded  with  tongue  joints,  the  joints  are  made  very  strong, 
through  the  extremities  being  made  to  extend  several  inches  along  the  handles,  as 
denoted  in  Fig.  122. 

A  small  wrench  that  is  only  about  1  ft.  long  is  made  of  only  one  piece  of  steel,  and 
it  is  not  necessary  to  select  soft  steel  for  welding,  the  stems  which  are  produced  from 
the  boss  being  made  long  enough  by  thinning  to  become  the  handles,  without  welding 
them  to  sei:)arate  pieces.  Large  tap  spanners,  also,  are  occasionally  made  in  this  way  if 
the  operators  have  access  to  steam  hammers  for  the  reducing.  For  economy,  small 
wrenches  are  often  made  of  old  files,  and  if  the  steel  is  not  too  brittle  to  be  properly 
thinned  for  the  handles,  strong,  hard,  durable  spanners  are  produced. 

All  the  holes  in  wrenches  are  square,  and  are  made  by  punching  and  drifting, 
having  proper  care  to  enlarge  the  holes  with  smooth  drifts,  so  that  only  a  very  little 
filing  shall  be  necessary.  The  handles  of  tap  wrenches  are  lathe-turned,  and  the 
junctions  of  the  stems  with  the  bosses  are  nicely  curved  with  springy  corner  tools. 

To  make  a  capstan  spanner  having  4  handles  extending  from  the  boss,  one  thick 
piece  for  the  boss  is  necessary,  and  4  straight  pieces  for  the  handles ;  these  are  welded 
to  the  boss  part  by  means  of  stems  that  are  produced  from  the  boss  by  thinning. 

The  outer  shape  of  the  boss  should  be  square,  not  circular ;  and  to  i^roduce  a  boss 
which  is  to  be  4  in.  long  and  about  4  in.  square,  a  piece  of  soft  steel  bar  should  be 
selected  which  is  about  4^  in.  square,  whicli  will  allow  a  trimming  to  shape  the  boss 
after  it  is  sproad  with  punching  and  drifting,  the  length  of  the  piece  being  about 


Forging  and  Finishing. 


83 


9  in.,  that  there  may  be  ample  metal  for  the  4  stems,  in  addition  to  the  hnm.  This 
piece  is  first  fullered  at  each  side  of  the  intended  boss,  and  tiiiuncd,  to  form  a  lump  in 
the  middle,  and  which  shall  extend  from  only  one  side,  as  shown  in  Pig.  123;  the  two 
thinner  portions  are  next  punched  with  a  round  punch  to  make  2  holes  near  the  boss, 
similar  to  those  in  Fig.  124 ;  a  slip  is  next  made  from  each  hole,  to  make  the  2  .stems 
or  arms  into  4 ;  these  are  separated,  and  the  juncJtions  fullered  to  make  a  rou^h  4-arm 


118. 


121. 


E 


120. 


119. 


'Bzn^^^: 


D 


122. 


□  Gn 


j^ 


123. 


124. 


125. 


126. 


12?. 


boss  denoted  by  Fig.  125.  The  square  hole  is  next  punched  in  the  boss,  by  commencing 
with  a  very  taper  square  punch,  which  is  driven  from  both  ends  of  the  hole,  the 
punch  being  placed  to  make  each  corner  of  the  hole  opposite  one  of  tlie  4  arms.  After 
punching,  square  drifts  are  used  to  enlarge  the  hole,  and  a  hammering  is  given  to  the 
boss  while  a  drift  is  in  the  hole,  and  the  boss  at  welding  heat,  which  makes  it  rather 
more  fibrous  than  before.  The  junctions  of  the  arms  are  next  shaped  with  a  fuller  and 
set  hammer,  and  the  arms  lengthened  to  a  convenient  length,  that  the  boss  may  not  be 
too  near  the  anvil  while  welding  the  handles  to  the  stems  of  the  boss.  The  final  shaping 
of  the  boss  consists  in  cutting  off  superfluous  metal  with  a  flat  chisel  and  a  gouge  chisel, 

G  2 


84  Forging  and  Finishing. 

and  smoothing  it  ■with  a  set  hammer  or  flatter,  also  with  a  fuller  at  the  junctions^ 
while  a  drift  of  the  finished  size  of  the  hole  remains  in  it.  A  boss  of  this  class  requires- 
a  careful  trimming  to  shape  it  at  the  conclusion  of  forging,  to  avoid  a  lengthy  shaping 
■while  cold,  especially  because  it  cannot  be  turned  in  a  lathe.  The  boss,  having  its 
arms  at  right  angles  to  each  other,  and  reduced  to  a  proper  thickness,  is  represented  by- 
Fig.  126. 

The  circular  boss,  shown  by  Fig.  127,  has  an  elegant  appearance,  and  can  be  lathe- 
turned  to  partly  shape  it ;  but  such  a  boss  requires  more  metal  around  a  square  hole  than 
is  necessary  for  a  square  boss  of  the  same  strength.  When  bosses  having  4  arms,  or 
3  arms,  are  being  made  in  considerable  numbers,  each  one  can  be  easily  shaped  in 
a  shaping  mould,  which  is  fitted  to  a  steam-hammer  anvil. 

Adjusting  surfaces  by  hammering. — One  of  the  most  interesting  uses  of  the  hammer 
is  for  stretching  plates  of  metal.  Blows  applied  upon  the  surface  of  a  straight  piece 
of  metal  will  cause  the  side  struck  to  rise  up  and  become  convex,  and  render  the  other 
side  concave.  This  process  is  termed  "  paning  "  or  "  pening,"  from  the  pane  or  pene  of 
the  hammer  being  generally  used  to  perform  it ;  it  is  resorted  to  for  straightening^ 
plates,  correcting  the  tension  of  circular  saws,  &c.,  and  has  recently  been  made  the 
subject  of  a  most  instructive  lecture  before  the  Franklin  Institute,  by  Joshua  Rose,  from, 
which  the  following  abstract  is  taken. 

Supposing  you  have  a  -J-in.  plate  with  a  dent  in  the  middle,  on  laying  one  end  on  aa 
anvil,  holding  up  the  other  in  your  left  hand,  and  springing  the  plate  up  and  down 
with  your  right  hand,  if  you  watch  the  plate,  you  will  see  that  as  you  spring  it  the 
middle  moves  most,  and  the  part  that  moves  is  a  "  loose  "  place.  The  metal  round  about 
it  is  too  short  and  is  under  too  much  tension.  Now,  if  you  hammer  this  loose  place  you 
will  stretch  it  and  make  it  wide,  so  hammer  the  places  round  about  it  that  move 
the  least,  stretching  them  so  that  they  will  pull  the  loose  place  out.  With  a  very- 
little  practice  you  can  take  out  a  loose  place  quite  well ;  but  when  it  comes  to  a  thick  plate, 
the  case  is  more  difficult,  because  you  cannot  bend  the  plate  to  find  the  tight  and  loose 
places,  so  you  stand  it  on  edge,  and  between  you  and  the  window  the  lights  and  shades 
show  the  high  and  low  patches.  Fig.  128  represents  what  is  called  the  "  long  cross-face  '* 
hammer  used  for  the  first  part  of  the  process,  which  is  termed  the  "  smithing."  The 
face  that  is  parallel  to  the  handle  is  the  long  one,  and  the  other  is  the  cross-face.  These 
faces  are  at  right  angles  one  to  the  other,  so  that  without  changing  his  position  the  operator 
may  strike  blows  that  will  be  lengthways  in  one  direction,  as  at  a,  in  Fig.  129,  and 
by  turning  the  other  face  towards  the  work  he  may  strike  a  second  series  standing 
as  at  h.  Now,  suppose  we  had  a  straight  plate  and  delivered  these  two  series  of 
blows  upon  it,  and  it  is  bent  to  the  shape  shown  in  Fig.  130,  there  being  a  straight  wave 
at  a,  and  a  seam  all  across  the  plate  at  h,  but  rounded  at  its  length,  so  that  the  plate  will 
be  highest  in  the  middle,  or  at  c,  if  we  turn  the  plate  over  and  repeat  the  blows  against 
the  same  places,  it  will  become  flat  again. 

To  go  a  little  deeper  into  the  requirements  of  the  shape  of  this  hammer,  for  straighten- 
ing saws  both  faces  are  made  alike,  being  rounded  across  the  width  and  slightly 
rounded  in  the  length,  the  amount  of  this  rounding  in  either  direction  being  important, 
because  if  the  hammer  leaves  indentations,  or  what  are  technically  called  "  chops,"  they 
will  appear  after  the  saw  has  been  ground  up,  even  though  the  marks  themselves  are 
ground  out;  because  in  the  grinding  the  hard  skin  of  the  plate  is  removed,  and  it 
goes  back  to  a  certain,  but  minute,  extent  towards  its  original  shape.  This  it  will  do 
more  in  the  spaces  between  the  hammer  blows  than  it  will  where  the  blows  actually  fell, 
giving  the  surface  a  slightly  waved  appearance. 

The  amount  of  roundness  a-cross  the  face  regulates  the  widths,  and  the  amount  of 
roundness  in  the  face  length  regulates  the  length  of  the  hammer  marks  under  any  given 
force  of  blow.  As  the  thicker  the  plate  the  more  forcible  the  blow,  therefore  the  larger 
the  dimensions  of  the  hammer  mark.    This  long  cross-face  is  used  again  after  the  saws 


Forging  and  Finishing. 


85 


iiave  been  ground  wp,  but  the  faces  are  made  more  nearly  flat,  so  that  the  marks  will  not 
sink  so  deeply,  it  being  borne  in  mind,  however,  that  in  no  case  must  they  form 
distinct  indentations  or  "  chops." 

Fig.  131  is  a  "twist"  hammer,  used  for  precisely  the  same  straightening  purposes  as 
the  long  cross-face,  but  on  long  and  heavy  plates,  and  for  the  following  reasons. 

When  the  operator  is  straightening  a  short  saw,  he  can  stand  close  to  tho  spot 
he  is  hammering,  and  the  arm  using  the  hammer  may  bo  well  bent  at  tho  elbow, 
which  enables  him  to  see  the  work  plainly,  and  does  not  interfere  with  the  use  of  the 


128. 


129. 


130. 


a. 


I  III  „>,/ 
I'm '/!/:! 


hammer,  while  the  shape  of  the  smithing  hammer  enables  him  to  bend  his  elbow  and 
still  deliver  the  blows  lengthways,  in  the  required  direction.  But  when  a  long  and 
ieavy  plate  is  to  be  straightened,  tho  end  not  on  the  anvil  must  be  supported  with  the 
Jeft  hand,  and  it  stands  so  far  away  from  the  anvil  that  he  could  not  bend  his  elbow 
and  still  reach  the  anvil.  With  the  twist  hammer,  however,  he  can  reach  his  arm  out 
straight  forward  to  the  anvil,  to  reach  the  work  there,  while  still  holding  up  the  other 
end,  which  he  could  not  do  if  his  elbow  were  bent.  By  turning  the  twist  hammer 
over  he  can  vary  the  direction  of  the  blow  the  same  as  with  the  long  cross-face. 

Both  these  hammers  are  used  only  to  straighten  the  plates,  and  not  to  regulate  their 
tension,  for  a  plate  may  be  flat  and  still  have  in  it  unequal  strains ;  that  is  to  say,  there 
may  exist  in  different  locations  internal  strains  that  are  not  strong  enough  to  bend  tho 
plate  out  of  truth  as  it  is,  but  which  will  tend  to  do  so  if  the  slightest  influence  is 
■exerted  in  their  favour,  as  will  be  the  case  when  the  saw  is  put  to  work.  When  a  plate 
is  in  this  condition,  it  is  said  to  have  unequal  tension,  and  it  is  essential  to  its  proper 
use  that  this  be  remedied. 

The  existence  of  unequal  tension  is  discovered  by  bending  the  plate  with  the  hands, 
as  has  been  already  mentioned,  and  it  is  remedied  by  the  use  of  the  dog-head  hammer, 
shown  in  Fig.  132,  whose  face  is  rounded  so  that  the  effects  of  its  blow  will  extend  equally 
all  round  the  spot  struck.  It  will  be  readily  understood  that  the  effects  of  the  blow 
delivered  by  the  smithing,  or  by  the  twist  hammer,  will  be  distributed  as  in  Fig.  133,  at 
a,  6,  while  those  of  the  dog-head  will  be  distributed  as  at  Fig.  133,  c,  gradually  diminish- 
ing as  they  pass  outwards  from  the  spot  struck ;  hence  the  dog-head  exerts  the  most 
•equalized  effect. 

Now,  while, the  dog-head  is  used  entirely  for  regulating  the  tension,  it  may  also  bo 


86 


FOEGING   AND   FINISHING. 


132. 


133. 


used  for  the  same  purposes  as  either  the  long  cross-faced  or  the  twist  hammer,  because 

the  smith  operates  to  equalize  the  tension  at  the  same  time  that  he  is  taking  down  the 

lumps ;  hence  he  changes  from  one  hammer  to  the  other  in  an  instant,  and  if,  after 

regulating  the  tension  with  the  dog-head,  he  should  happen  to  require  to  do  some 

smithing,  before  regulating  the  tension  in  another,  he  would  go 

right  on  with  the  dog-head  and  do  the  intermediate  smithing 

without  changing  to  the  smitliing  hammer.     Or,  in  some  cases, 

he  may  use  the  long  cross-face  to  produce  a  similar  effect  to 

that  of  the   dog-head,  by  letting  the  blows  cross  each  other, 

tbu;j  distributing  the  hammer's  effects  more  equally  than  if  the 

blows  all  lay  in  one  direction. 

In  circular  saws,  which  usually  run  at  high  velocity,  there 
is  generated  a  centrifugal  force  that  is  sufficient  to  actually 
stretch  the  saw  and  make  it  of  larger  diameter.  As  the  outer 
edge  of  the  saw  runs  at  greater  velocity  than  the  eye,  it 
stretches  most,  and  therefore  the  equality  of  tension  through- 
out the  saw  is  destroyed,  the  outer  surface  becoming  loose  and 
causing  the  saw  to  wobble  as  it  revolves,  or  to  run  to  one  side 
if  one  side  of  the  timber  happens  to  be  harder  than  the  other, 
as  in  the  case  of  meeting  the  edge  of  a  knot. 

The  amount  of  looseness  obviously  depends  upon  the 
amount  the  saw  expands  from  the  centrifugal  force,  and  this  clearly  depends  upon  the 
speed  the  saw  is  to  run  at,  so  the  saw  straightener  requires  to  know  at  what  speed  the 
saw  is  to  run,  and,  knowing  this,  he  gives  it  more  tension  at  the  outside  than  at  the 
eye  ;  or,  in  other  words,  while  the  eye  is  the  loosest, 
the  tension  gradually  increases  towards  the  circum- 
ference, the  amount  of  increase  being  such  that  when 
the  saw  is  running  the  centrifugal  force  and  con- 
sequent stretching  of  the  saw  will  equalize  the 
tension  and  cause  the  saw  to  run  steadily. 

In  circular  saws  the  combinations  of  tight  and 
loose  places  may  be  so  numerous  that  as  the  smith 
proceeds  in  testing  with  the  straight-edge  he  marks 
them,  drawing  a  circular  mark,  as  at  g,  in  Fig.  134, 
to  denote  loose,  and  the  zig-zag  marks  to  indicate  tight  places. 

To  cite  some  practical  examples  of  the  principles  here  laid  down,  suppose  we  have  in 
Figs.  135  and  136  a  plate  with  a  knick  or  bend  in  the  edge,  and  as  this  would  stiffen  the 
plate  there,  it  would  be  called  a  tight  place.  To  take  this  out,  the  hammer  marks  could 
be  delivered  on  one  side  radiating  from  the  top  of  the  convexity  as  in  Fig.  135,  and  on  the 
other  as  shown  radiating  from  the  other  end  of  the  concavity  as  in  Fig.  136,  the  smithing 
hammer  being  used.  This  would  induce  a  tight  place  at  a.  Fig.  135,  which  could  be 
removed  by  dog-head  blows  delivered  on  both  sides  of  the  plate.  Suppose  we  had  a 
plate  with  a  loose  place,  as  at  g  in  Fig.  137,  we  may  take  it  out  by  long  cross-face  blows, 
as  at  a  and  h,  delivered  on  both  sides  of  the  plate,  or  we  might  run  the  dog-head  on  both 
sides  of  the  plate,  both  at  a  and  at  b,  the  effect  being  in  either  case  to  stretch  out  the 
metal  on  both  sides  of  the  loose  place  g,  and  pull  it  out.  In  doing  this,  however,  we 
shall  have  caused  tight  places  at  e  and  /,  which  we  remove  with  dog-head  blows,  as 
shown.  If  a  plate  had  a  simj^le  bend  in  it,  as  in  Fig.  138,  hammer  blows  would  first  be 
delivered  on  one  side,  as  at  a,  and  on  the  other  side,  as  at  b.  A  much  more  complicated 
case  would  be  a  loose  place  at  g,  in  Fig.  139,  with  tight  places  at  li,  i,  k,  I,  for  which  the 
hammer  blows  would  be  de]ivere<l  as  marked,  and  on  both  sides  of  the  plate.  Another 
complicated  case  is  given  in  Fig.  140,  g  being  two  loose  places,  with  tight  places 
between  them  and  on  each  side.     In  this  case,  the  hammering  with  the  long  cross- 


Forging  and  Finishing. 


87 


'ace  would  induce  tight  places  at  d  and  e,  requiring  hammer  blows  as  denoted  by  the 
narks. 

Eose  had  some  examples  to  illustrate  how  plainly  bending  a  plate  will  kIiow  its 
;ight  and  loose  places.    With  a  rectangular  piece  of  plate  tliat  is  loose  in  tiie  middle, 


134. 


IM. 


135. 


137. 


;he  straight-edge  lies  flat  on  it ;  but  if  you  try  to  bend  the  middle  of  the  plate  downwards 
ivith  your  hands,  you  will  see  that  it  goes  down  instantly,  the  straight-edge  showing  a 
.arge  hollow  in  the  middle,  as  in  Fig.  141,  the  same  thing  occurring  with  the  straight- 


138. 


139. 


0     0     0    0  0     0    „ 


O    0    0     0   0 


0      0  0       0   "(,   °0    ° 


3dge  tried  on  both  sides  of  the  plate.  Another  piece  is  tight  in  the  middle,  and  when 
jrou  try  to  bend  its  middle  downwards  in  precisely  the  same  way,  it  comes  upwards, 
ind  the  straight-edge  shows  it  to  be  round  as  in  Fig.  142.    In  the  first  case  the  middle 


140. 


^.///MC 


142. 


actually  moves,  because  it  is  loose ;  in  the  second  place  the  edges  move,  because  they 

are  loose. 

With  two  circular  saws,  one  tight  and  one  loose  at  the  centre,  the  same  thing  occurs ; 


88  Forging  and  Finishing. 

for  if  you  bend  the  loose  one  down,  it  goes  down,  leaving  a  wide  space  between  the  eye 
of  the  saw  and  the  straight-edge  ;  while  if  you  try  to  bend  the  middle  of  the  light  one 
down  it  refuses  to  go  there,  but  goes  at  the  outside,  leaving  the  straight-edge  resting  on 
the  middle.  Here,  again,  then,  the  part  that  is  loose  moves  the  most.  These  examples 
are  simple  cases,  but  they  impart  a  general  knowledge  of  the  principles  involved  in  the 
skilful  use  of  the  hammer. 

Red-lead  Joints. — In  every  case  in  which  steam  is  used  at  a  pressure  exceeding  that 
of  the  atmosphere,  either  as  a  motive  power  or  a  heating  agent,  it  is  necessary  to  make 
tlie  machinery  or  piping  connected  therewith  in  many  pieces,  for  obvious  reasons,  the 
chief  of  which  is  convenience  in  manufacture,  and  wherever  these  are  joined  together  to 
hold  or  convey  steam  it  is  necessary  to  make  the  joints  steamtight.  For  this  purpose 
there  are  almost  innumerable  methods,  but  we  only  intend  giving  briefly  a  few  notes 
on  those  in  which  red  lead  is  used,  which  are  most  familiar  to  those  connected  with 
the  trade  of  an  engineer ;  but  notwithstanding  this  familiarity,  nineteen  out  of  twenty 
mechanics  have  very  erroneous  ideas  on  the  subject,  and  consequently  many  joints  are 
fhe  cause  of  much  delay,  trouble,  and  expense,  which  could  easily  have  been  avoided  if 
the  general  principles  were  understood.  The  fundamental  principle  of  all  joint-making 
is,  that  the  thinner  the  joint  the  stronger  and  more  durable  it  is. 

(a)  Flat-faced  joints,  as  pipe  flanges,  cylinder  covers,  &c. — Each  face  must  have  all 
the  old  lead  removed,  and  then  be  wiped  over  with  a  piece  of  oily  waste  (boiled  linseed 
oil).  The  lead  must  be  thoroughly  worked,  either  by  machine  or  by  hand,  to  make  it 
soft  and  pliable,  and  also  to  remove  all  grit  and  lumps.  It  should  then  be  rolled  in  the 
hands  into  thin  ropes,  about  5  in.  diameter,  and  laid  on  once  round  inside  the  bolt  holes. 
The  2  faces  must  now  be  brought  together  carefully,  and  tightened  up  equally  all 
round,  by  screwing  up  opposite  bolts,  so  as  to  avoid  getting  one  side  closer  than  another. 
Tarred  twine,  hemp,  string,  wire  gauze,  &c.,  should  be  studiously  avoided  wherever 
possible,  as  it  prevents  the  faces  from  being  brought  into  close  contact.  There  are 
certain  rough  jobs  where  it  may  be  permitted,  but  a  joint  so  made  is  never  so  durable, 
and  very  clumsy.  When  joints  are  accurately  faced,  by  scraping  or  otherwise,  as  in 
locomotive  practice,  nothing  but  liquid  red  lead  is  used,  made  of  white  lead  mixed  with 
boiled  oil  to  the  coneistency  of  paint ;  they  are  of  exceptional  durability. 

(h)  Joints  between  male  and  female  threads,  such  as  screwed  pipes  and  sockets,  bolts 
or  studs  screwed  into  boiler  plates,  &c. — In  these  cases  liquid  red  lead  is  used,  and 
should  be  put  on  the  female  thread  for  inside  pressure,  on  the  male  for  outside  pressure, 
as  then  the  steam  in  each  case  forces  any  surplus  lead  into  the  thread,  and  forma  a  more 
reliable  joint,  or  rather  assists  it ;  whereas,  when  it  is  applied  in  the  reverse  way,  as 
generally  done,  the  threads  are  left  quite  bare  and  clear,  leaving  nothing  to  assist  the 
joint. 

These  methods,  broadly  speaking,  apply  just  the  same  to  the  various  compositions 
sold  as  substitutes  for  lead,  the  chief  advantages  claimed  for  them  being  cheapness  and 
durability  ;  but  they  can  never  surpass,  or  even  equal  it,  if  it  be  only  used  as  explained, 
esi^eciilly  if  a  little  common  sense  be  applied  in  special  cases. 

Rust  Joints. — "  Rust "  cement,  known  also  as  cast  iron  cement,  and  by  other  names, 
is  used  for  caulking  the  joints  of  cast  iron  tanks,  pipes,  &c.  It  is  composed  of  cast  iron 
turnings,  pounded  so  that  they  will  pass  through  a  sieve  of  8  meshes  to  the  in. ;  to  these 
are  added  powdered  sal-ammoniac,  and  sometimes  flowers  of  sulphur.  The  ingredients 
having  been  mixed  are  damped,  and  soon  begin  to  heat.  They  are  then  again  well 
mixed  and  covered  with  water.  The  exact  proportions  of  the  ingredients  vary.  A 
simple  form  is  I  oz.  sal-ammoniac  to  1  cwt.  iron  turnings.  The  following  are  recom- 
mended by  Molesworth : — 

Quick-setting  Cement. — 1  sal-ammoniac  by  weight;  2  flowers  of  sulphur;  80  iron 
borings. 

Slow-setting  Cement. — 2  sal-ammoniac ;  1  flowers  of  sulphur ;  200  iron  borings. 


Forging  and  Finishing. 


89 


143. 


The  latter  cement  being  the  best  if  the  joint  is  not  required  for  immediate  use.  la 
the  absence  of  sal-ammoniac  the  urine  of  an  animal  may  bo  substituted.  The  cement 
will  keep  for  a  long  time  under  water.  Its  efficacy  depends  upon  the  expansion  of  the 
iron  in  combining  -with  the  sal-ammoniac.  The  joints  may  bo  undone  by  heating  the 
part  to  redness  and  jarring  by  hammer  blows;  paraffin  or  benzolino  applied  to  the  joint 
will  sometimes  assist. 

liivets. — The  dimensions  of  rivets  and  of  the  plates  at  the  joint  may  be  calculated  by 
the  same  rules  as  for  single  bolts.  If  it  is  a  joint  subject  to  tenision,  as  in  Fig.  143,  the 
eflfective  strength  of  the  joint 
and  of  the  plate  is  the  resistance 
of  the  cross-sections  a  h  and  c  d 
to  tension,  and  of  the  cross- 
sections  h  e  and  cf  to  shearing. 
If  it  is  a  joint  subject  to  com- 
pression, as  in  Fig.  144,  the 
effective  strength  is  the  re- 
sistance of  the  section  g  i  h  to 
compression.  Hence,  in  a  tensile 
lap  joint  the  size  of  the  rivets 
should  be  as  small  as  possible, 
and  the  sections  of  the  parts 
a  b  c  d  as  large  as  possible ;  and 
in  a  compressile  lap  joint  the 
size  of  the  rivets  should  be  as  large  as  possible. 

Lap  joint  is  the  name  given  to  a  riveted  joint  when  the  plates  overlap  each  other. 
In  a  single  rivet  lap  joint,  as  in  Fig.  145,  the  whole  tensile  or  compressile  strain  being 
divided  amongst  the  spaces  between  the  rivets  determines  the  interval  of  them.  And 
the  whole  shearing  strain  being  divided  amongst  the  sections  ab,  c  d,  &c.,  determines 


ci 


114. 


145. 


146. 


JT\ 


-CT- 


!  ^■-■ 

\ 

the  amount  of  overlap.  Fairbairn  considers  that  the  strength  of  such  a  joint  under 
tension  is  only  0-56  of  tliat  of  the  solid  plate  of  the  same  general  cross-sections. 

In  a  double  rivet  lap  joint  the  amount  of  overlap  and  the  intervals  between  the  rows 
of  rivets  both  ways,  and  the  size  of  the  rivets,  are  all  determined  by  the  above  considera- 
tions, and  by  the  rules  for  bolts.  Fig.  14G  shows  the  joint  recommended  by  Hamber  for 
tensile  strains. 

Fig.  147  shows  the  joint  he  recommends  for  compressive  strains. 

In  practice  the  diameter  of  the  rivets  is  generally  made  a  little  more  than  the  tliick- 
ness  of  the  plate,  and  the  interval  is  from  2  to  4  times  the  diameter,  according  to  the 
closeness  of  the  joint  required. 

The  practice  in  H.M.  Dockyard  at  Chatham,  in  the  construction  of  iron  ships,  is  (o 


/'"N  r^   1^- 

>  rA  r-^ 

.                                                                                      1 

'                                                                             • 

O    OiO     O 

O     i     O 
O    O^O     O 


a 


90  FOEGING   AND   FINISHING. 

use  rivets  ratber  larger  in  diameter  than  the  thickness  of  the  plate,  and  at  intervals  from 

2  to  4  times  the  diameter.  Thornton  states  that  a  watertight  joint  can  be  formed  with 
single  riveting  at  intervals  of  4  diameters ;  double  riveting  is  commonly  used,  the  first 
row  being  placed  at  a  distance  of 

at  least  one  diameter  (of  rivet) 
from  the  edge  of  the  plate,  and 
the  second  row  at  about  3  dia- 
meters from  the  first.  These 
rules  determine  the  length  of 
what  is  called  the  butt-plate,  or 
fishing-piece.  The  rivets  in  the 
second  row  are  placed  directly 
ojiposite  those  in  the  first  row, 
and  not  diagonally  opposite  the 

spaces.  In  all  exterior  plates  the  outer  rivet-holes  are  countersunk  and  the  rivets 
hammered  flush. 

SOLDERING-. — Soldering  is  the  art  of  forming  joints  between  metallic  surfaces 
by  the  application  of  molten  alloys. 

Solders. — Alloys  employed  for  joining  metals  together  are  termed  "  solders,"  and 
they  are  commonly  divided  into  two  classes :  hard  and  soft  solders.  The  former  fuse 
only  at  a  red  heat,  but  soft  solders  fuse  at  comparatively  low  temperatures. 

One  of  the  most  easily  fusible  metals  is  an  alloy  of  2  parts  bismuth,  1  tin,  and 
1  lead ;  tin  is  the  most  fusible  of  these  three  metals,  melting  at  455°  F.  (235°  C), 
but  tliis  alloy  melts  at  199J°  F.  (93°  C),  or  a  little  below  the  boiling-point  of  water. 
By  diminishing  the  quantity  of  bismuth  in  the  alloy,  the  point  of  fusion  may  be 
made  to  vary  between  212°  F.  (100°  C),  and  329°  F.  (200°  C),  and  thus  it  is  an  easy 
matter  to  form  a  solder  which. shall  fuse  at  any  required  temperature  between  these 
limits,  for  electrical  puri^oses,  steam-boiler  plugs,  &c.  The  following  are  the  best 
recipes  for  the  common  solders  : — For  aluminium-bronze :  (o)  88  •  88  gold,  4  •  68  silver, 
6*44  copper;  (h)  54 '4  gold,  27  silver,  18 "6  copper,  (c)  Melt  20  parts  of  aluminium 
in  a  suitable  crucible,  and  when  in  fusion  add  80  of  zinc.  When  the  mixture  is 
melted,  cover  the  siurface  with  some  tallow,  and  maintain  in  quiet  fusion  for  some 
time,  stirring  occasionally  with  an  iron  rod.  Then  pour  into  moulds,  (d)  15  parts 
aluminium  and  85  of  zinc;  (e)  12  aluminium  and  88  zinc;  (/)  8  aluminium  and 
92  zinc ;  all  of  these  alloys  are  prepared  as  (c).      The  flux  recommended  consists  of 

3  parts  copaiba  balsam,  1  of  Venetian  turpentine,  and  a  few  drops  of  lemon-juice. 
The  soldering-iron  is  dipped  into  this  mixture. 

For  hrassicork :  (a)  equal  parts  of  copjier  and  zinc ;  (b)  for  the  finer  kinds  of 
work,  1  part  silver,  8  copper,  8  zinc. 

For  copper :  (o)  3  parts  copper,  I  zinc;  (6)  7  copi^er,  3  zinc.  2  tin. 

Hard  solder :  86  •  5  copper,  9  •  5  zinc,  4  tin. 

Hard  solder  for  gold  :  18  parts  I8-carat  gold,  10  silver,  10  pure  copper. 

Hard  silver  solder  :  («)  4  parts  silver,  I  copper  ;  {L)  2  silver,  1  brass  wire ;  these  are 
employed  for  fine  work ;  the  latter  is  the  more  readily  fusible ;  (c)  equal  parts  copper 
and  coin  silver ;  requires  higher  temperature  than  h,  but  will  not  "  burn,"  is  as  fluid 
as  water,  and  makes  a  far  sounder  joint. 

Hard  spelter  solder:  2  parts  copper;  1  zinc;  this  solder  is  used  for  ironwork, 
gun-metal,  &c. 

For  jewellers :  (a)  19  parts  fine  silver,  10  brass,  1  copper ;  (h)  for  joining  gold. 
24  parts  gold,  2  silver,  1  copper. 

Middling  hard  solder  :  4  parts  scraps  of  metal  to  be  soldered,  1  zinc. 

For  pewterers:  (a)  2  parts  bismuth,  4  lead,  3  tin  ;  (b)  1  bismuth,  1  lead,  2  tin; 
the  latter  is  best  applied  to  the  rougher  kinds  of  works. 


Soldering — Solders. 


91 


For  sealing  iron  in  stone :  2  lead,  1  zinc. 

For  sealing  tops  of  canned  goods:  IJ  lb.  lead,  2  lb.  tin,  2  oz.  bismutli ;  the  lead 
is  melted  first,  the  tin  added  next,  and  finally  the  bismuth  stirred  in  well  just  before 
pouring.     This  makes  a  soft  solder,,  and  the  cans  do  not  take  much  heat  to  open  them. 

Soft  solder :  1  lead,  2  tin. 

Soft  solder  for  joining  electrotype  plates :  67  parts  lead,  33  tin. 

For  steel :  19  parts  silver,  3  copper,  1  zinc. 

For  tinned  iron  ■•  7  lead,  1  tin. 

The  following  table  exhibits  the  composition  and  characters  of  a  number  of 
solders : — 


No. 


1 

2 
3 

4 
5 
6 

7 

8 

9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 


Name. 


Plumbers'  coarse  solder 

„  sealed      „ 

„  fine  „  ..      .. 

Tinners'  solder      

„        fine  solder      

Hard  solder  for  copper,  brass,  iron 


more  fusible  than  6  or  7  . .  / 
Hard  solder  for  copper,  brass,  iron 
Silver  solder  for  jewellers    . . 

„  plating  ..  .. 
„  silver,  brass,  iron 
„  steel  joints 
„    more  fusible 

Gold  solder 

Bismuth  solder      


5> 


Pewterers'  solder 


Composition. 


Tin  1,  Lead  3 

1  2 

1  „        1  ..  .. 

H    „    1      ..     .. 

2  „     1       ..      .. 

Copper  2,  zinc  1  . . 
Good  tough  brass  5,  zinc  1 

Copper  1,  zinc  1 

Good  tough  plate  brass  .. 
Silver  19.  copper  1,  brass  1 
2,  brass  1 

1  „  1  ..  .. 
19,  copper  1,  brass  1 
5,  brass  5,  zinc  5  . . 
Gold  12,  silver  2,  copper  4 
Lead  4,  tin  4,  bismuth  1 
8    „    3         „  1 

2     „    2         „  1 

2    „    1         „  2 

o     „     o  ,,  o 

4     „    3 


5) 
)> 

1» 


)5 


Flu^ 

R 

R 

R 

Ror 

Z 

Ror 

Z 

B 

B 

B 

B 

B 

B 

B 

B 

B 

B 

Ror 

z 

Ror 

z 

Ror 

z 

Ror 

z 

Ror 

z 

Ror 

z 

Fluxing  point. 


800  F.  (427  C.) 
441  F.  (227  C.) 
370  F.  (188  C.) 
334  F.  (108  C.) 
340  F.  (171  C.) 


320  F.  (160  C.) 
310  F.  (154  C.) 
292  F.(144C.) 
236  F.  (113  C.) 
202  F.  (94  C.) 


Abbreviations  :  R,  Rosin  ;  B,  Borax  ;  Z,  Zinc  Chloride. 


Advantage  may  be  taken  of  the  different  degrees  of  fusibility  of  the  solders  in  the 
table  to  make  several  joints  in  the  same  piece  of  work.  Thus,  if  the  first  joint  has 
been  made  with  fine  tinners'  solder,  there  would  be  no  danger  of  melting  it  in 
making  a  joint  near  it  with  bismuth  solder  No.  16,  and  the  melting-point  of  both 
is  far  enough  removed  from  No.  19  to  be  in  no  danger  of  fusion  during  the  use  of 
that  solder.  Soft  solders  do  not  make  malleable  joints.  To  join  brass,  copper,  or 
iron,  so  as  to  have  the  joint  very  strong  and  malleable,  hard  solder  must  be  used.  For 
this  purpose.  No.  12  will  be  found  excellent ;  though  for  iron,  copper,  or  very  infusible 
brass,  nothing  is  better  than  silver  coin,  rolled  out  thin,  which  may  be  done  by  any 
silversmith  or  dentist.  This  makes  decidediy  the  toughest  of  all  joints,  and,  as  a 
little  silver  goes  a  long  way,  it  is  not  very  expensive.  To  obtain  hard  solders  of 
uniform  composition,  they  are  generally  granulated  by  pouring  them  into  water  through 
a  wet  broom.  Sometimes  they  are  cast  in  solid  masses,  and  reduced  to  powder  by 
filing.  Nos.  10,  11,  12,  13,  14,  and  15  are  generally  rolled  into  thin  plates,  and  some- 
times the  soft  solders,  especially  No.  21,  are  rolled  into  sheets,  and  cut  into  narrow  strips, 
■which  are  very  convenient  for  small  work  that  is  to  be  heated  by  lamp.  Hard  solders, 
Nos.  C,  7,  8,  and  9,  are  usually  reduced  to  powder,  either  by  granulation  or  filing,  and  then 


92  Soldering — Solders. 

spread  along  the  joints  after  being  mixed  with  borax  which  has  been  fused  and  powdered. 
It  is  not  necessary  that  the  grains  of  solder  should  be  placed  between  the  pieces  to  be 
joined,  as  with  the  aid  of  the  borax  they  will  sweat  into  the  joint  as  soon  as  fusion  takes 
place.  The  best  solder  for  platinum  is  fine  gold.  The  joint  is  not  only  very  infusible, 
but  is  not  easily  acted  upon  by  common  agents.  For  German  silver  joints.  No.  14  is 
excellent. 

When  brass  is  soldered  with  soft  solder,  the  difference  in  colour  is  so  marked  as  to 
direct  attention  to  the  spot  mended.  The  following  method  of  colouring  soft  solder  is 
given  by  the  MetaUarbeiter :  First  prepare  a  saturated  solution  of  copper  sulphate 
(bluestone)  in  water,  and  apply  some  of  this  on  the  end  of  a  stick  to  the  solder.  On 
touching  it  with  a  steel  or  iron  wire  it  becomes  coppered,  and  by  repeating  the 
experiment  the  deposit  of  copper  may  be  made  thicker  and  darker.  To  give  the  solder 
a  yellower  colour,  mix  1  part  of  a  saturated  solution  of  zinc  sulphate  with  2  of  copper 
sulphate,  apply  this  to  the  coppered  spot,  and  rub  it  with  a  zinc  rod.  The  colour  can 
be  still  further  improved  by  applying  gilt  powder  and  polishing.  On  gold  jewelry  or 
coloured  gold,  the  solder  is  first  coppered  as  above,  then  a  thin  coat  of  gum  or  isinglass 
solution  is  applied,  and  bronze  powder  is  dusted  over  it,  which  can  be  polished  after  tie 
gum  is  dry,  and  made  very  smooth  and  brilliant ;  or  the  article  may  be  electroplated 
with  gold,  and  then  it  will  all  have  the  same  colour.  Ou  silverware,  the  coppered  spots 
of  solder  are  rubbed  with  silvering  powder,  or  polished  with  the  brush  and  then  carefully 
scratched  with  the  scratch-brush,  then  finally  polished. 

Burning,  or  Autogenous  Soldering. — The  process  of  uniting  two  or  more 
pieces  of  metal  by  partial  fusion  is  called  "  burning."  This  operation  differs  from  the 
ordinary  soldering,  in  the  fact  that  the  uniting  or  intermediate  metal  is  the  same  as 
those  to  be  joined,  and  generally  no  flux  is  used,  but  the  metals  are  simply  brought 
almost  to  the  fusing-point  and  united.  The  process  of  burning  is,  in  many  cases,  of 
great  importance ;  when  the  operation  is  successfully  performed,  the  work  is  stronger 
than  when  soldered,  for  all  parts  of  it  are  alike,  and  will  expand  and  contract  evenly 
■when  heated,  while  solders  often  expand  and  contract  more  or  less  than  the  metals  which 
they  unite,  and  this  uneven  contraction  and  expansion  of  the  metal  and  solder  often 
tears  the  joint  apart ;  another  objection  to  soldering  is  that  the  solders  oxidize  either 
more  or  less  freely  than  the  metals,  and  weaken  the  joints,  as  is  the  case  if  leaden  vessels 
or  chambers  for  sulphuric  acid  are  soldered  with  tin,  the  tin,  being  so  much  more  freely 
dissolved  by  the  acid  than  the  lead,  soon  weakens  or  opens  the  joints. 

Fine  work  in  pewter  is  generally  burned  together  at  the  corners  or  sharp  angles, 
where  it  cannot  be  soldered  from  the  inside ;  this  is  done  that  there  may  be  no  difference 
of  colour  in  the  external  surface  of  the  work.  In  this  operation,  a  piece  or  strip  of  the 
same  pewter  is  laid  on  the  parts  to  be  united,  and  the  whole  is  melted  together  with  a 
large  soldering-iron  or  copper  bit,  heated  almost  to  redness ;  the  superfluous  metal  is  then 
•dressed  off,  and  leaves  the  surfaces  thoroughly  united,  without  any  visible  joint.  In 
burning  together  pewter  or  any  of  the  very  fusible  metals,  great  care  is  required  to  avoid 
melting  and  spoiling  the  work. 

Castings  of  brass  are  often  united  by  burning.  In  this  operation,  the  ends  of  the 
2  pieces  to  be  united  are  filed  or  scraped,  so  as  to  remove  the  outside  surface  or  scale ; 
they  are  then  embedded  in  a  sand  mould  in  their  proper  position,  and  a  shallow  or  open 
space  is  left  around  the  joint  or  ends  of  the  castings  ;  30  or  40  lb.  of  melted  brass  are 
then  poured  on  to  the  joint,  and  the  surplus  metal  is  allowed  to  escape  through  a 
flow-gate.  In  this  way  2  castings  may  be  united  so  that  they  are  as  solid  as  if  they  had 
been  cast  in  one  piece.  This  process  is  resorted  to  by  all  brassfounders  in  making  large 
and  light  castings,  such  as  wheels,  large  circular  rims,  &c. ;  when  too  largo  to  be  run  in 
one  piece,  they  are  usually  cast  in  segments  and  united  by  burning  together. 

Cast  iron  is  often  united  by  burning  together,  or,  more  properly,  burning  on,  for  in 
this  case  one  of  the  metals  added  or  united  is  in  the  fluid  state.     When  about  to  bum 


Soldering — Burning.  93 

on  to  a  piece  of  casting,  the  part  to  bo  united  to  is  scraped  or  filed  perfectly  clean,  and 
is  then  embedded  in  sand,  and  a  mould  of  the  desired  shape  is  formed  around  the 
casting ;  the  metal  is  then  poured  into  the  mould,  and  allowed  to  escape  through  a 
flow-gate  until  the  surface  of  the  casting  is  melted,  and  the  metals  unite,  the  same 
as  in  burning  together  brass  castings.  In  this  way,  small  pieces  that  have  broken  oft 
large  castings  are  burned  on,  and  cylinders  that  have  had  part  of  the  flanges  torn  oft"  by 
blowing  out  the  heads  are  repaired  by  burning  on  a  new  flange  or  the  part  that  has  been 
torn  oif.  In  burning  on  to  cast  iron  there  are  several  very  important  points  that  must 
be  observed  in  order  to  make  it  a  success.  The  ingate,  as  well  as  the  flow-gate,  should 
be  made  of  a  good  size,  so  that  the  molten  metal  may  be  flowed  through  them  rapidly 
if  necessary.  The  molten  iron  used  should  be  the  hottest  that  can  be  procured,  and 
in  pouring  it  into  the  gate  it  should  be  let  in  rapidly  at  first,  and  allowed  to  run  out 
freely  at  the  flow-gate,  so  as  to  prevent  its  being  chilled  upon  the  surface  of  the  casting. 
After  the  casting  has  been  heated  in  this  way,  the  metal  should  be  poured  and  flowed 
through  the  gates  slowly,  so  as  to  give  the  solid  metal  a  chance  to  melt  and  unite  with 
the  fluid  metal.  After  the  surface  of  the  metal  has  been  melted,  the  pouring  should 
be  urged,  so  as  to  unite  the  metals  more  thoroughly  ;  the  operation  should  be  continued 
for  some  time,  so  that  the  casting  may  be  more  thoroughly  heated,  and  not  be  so  liable  to 
crack  from  uneven  expansion  and  shrinkage. 

The  process  of  burning  together  or  mending  is  often  resorted  to  by  stove-plate 
moulders  for  stopping  small  holes  in  the  plates ;  this  is  done  by  laying  the  plate  on 
the  sand,  with  the  sand  firmly  tucked  under  the  part  to  be  mended  ;  a  little  sand  is  also 
put  on  top  of  the  plate,  around  the  part  to  be  mended,  so  as  to  prevent  the  iron  spread- 
ing over  the  plate ;  the  molten  iron  is  poured  on  the  part  to  be  mended,  until  the  edges 
are  fused,  and  the  surplus  metal  is  then  scraped  off  with  the  trowel  or  a  clamp  iron 
while  in  the  molten  state. 

The  simplest  method  of  burning  is  that  adopted  in  the  manufacture  of  leaden  tubs, 
tanks,  and  other  vessels,  the  success  of  the  operation  depending  more  upon  the 
quantity  and  state  of  the  materials  than  upon  the  skill  of  the  workman.  Thus  if  a 
round  or  square  tank  is  required,  a  piece  of  the  sheet  lead  sufficient  in  size  to  form  the 
sides  and  ends  of  the  tank,  or  the  hoop,  if  a  round  one,  is  bent  into  shape,  the  over- 
lapping ends  being  secured  by  a  few  touches  of  solder  or  a  few  nails,  driven  from  the 
inside,  so  as  to  keep  the  overlapping  edges  perfectly  close.  On  the  outside  of  the  joint  a 
piece  of  stout  brown  paper  is  pasted,  so  as  to  cover  the  whole  of  the  joint.  The  hoop 
or  parts  to  be  joined,  are  then  turned  downwards  on  to  the  casting  floor,  and  moulding 
sand  of  good  quality  is  packed  over  the  joint  to  about  5  or  6  in.  in  depth,  a  piece  of 
wood  about  |  in.  thick  being  placed  over  the  junction  of  the  edges,  while  the  sand  is 
being  rammed  together.  This  wood  is  to  form  the  runner  or  channel  for  the  molten 
metal,  and  must  be  slightly  longer  than  the  joint  to  be  made,  so  that  it  can  be  drawn 
out  lengthways.  The  sand  being  tolerably  firm,  cut  down  to  the  wood,  with  a  trowel, 
forming  a  sort  of  V-shaped  groove  along  nearly  the  whole  length  of  the  intended  joint, 
leaving  a  few  inches  of  the  wood  buried  at  one  end,  which  is  also  to  be  completely 
stopped.  When  the  wood  is  drawn  out,  which  is  the  next  operation,  the  other  end  of 
the  ''  runner "  is  to  be  stopped  up  to  a  greater  or  lesser  height,  according  to  the 
thickness  of  the  metal;  about  1  in.  is  usually  sufficient.  It  will  be  understood  that  we 
have  here,  as  it  were,  a  broad-mouthed  ditch  in  the  sand,  stopped  at  one  end,  and  with  a 
"bar"  1  in.  deep  at  the  other  ;  and  at  the  bottom  are  the  overlapping  edges  of  the  lead 
that  is  to  be  joined,  A  quantity  of  lead  is  then  melted  in  a  furnace,  and  brought 
to  a  heat  sufficient  to  melt  the  2  edges  in  the  metal  to  be  joined.  Everything  being 
in  readiness,  a  small  quantity  of  rosin  is  dusted  along  the  intended  joint  at  the  bottom 
of  the  runner,  and  a  bay  is  formed  to  catch  the  overflow  of  metal.  The  latter  is  then 
poured  in  steadily  but'  quickly,  giving  it  as  much  fall  as  possible,  and  keeping  up  the 
supply  till  by  means  of  a  trying  stick  it  is  known  that  the  cold  metal  of  the  edges  haa 


94  Soldering— Burnino:, 


o 


becu  melted.  The  overflow  end  is  theu  stopped  up,  and  more  metal  is  poured  in, 
the  molten  lead  being  kept  ready  to  fill  up  as  shrinkage  shows  itself.  "WTien  set,  the 
sand  is  removed,  and  the  "  runner,"  or  the  remains  of  the  metal  poured  on  the  joint,  is 
cut  off  with  a  chisel  and  mallet ;  the  surface  is  finished  off  with  a  scratch-brush  or 
wire-card.  The  paper  that  was  pasted  over  the  outside  will  have  fallen  off,  and  will 
be  seen  to  have  left  a  smooth  surface,  in  which  no  trace  of  a  join  is  visible.  The  secret 
of  success  lies  in  having  a  good  bed  of  sand,  plenty  of  hot  metal,  and  careful  attention 
to  the  shrinkage.  The  bottom  of  the  tub  or  tank  is  put  in  by  a  similar  process. 
The  hoop  or  sides,  when  the  tank  is  not  too  deep,  being  completely  sunk  in  a  hole 
in  the  casting-shop,  is  filled  up  with  sand  inside  and  out.  The  sand  is  then  removed 
from  the  inside  to  a  depth  equal  to  the  thickness  required  iu  the  bottom  of  the  tank, 
and  smoothed  over  well  with  the  trowel.  The  sand  outside  the  tank  must  be  rammed 
hard,  and  a  bay  left  all  round  to  take  the  overflow.  As  before,  rosin  is  sprinkled  over 
the  edge  of  the  metal,  and  the  melting-furnace  is  brought  close  to  the  work.  When  the 
metal  is  as  hot  as  possible,  2  or  more  men  take  a  ladleful  and  pour  along  the  edge,  and 
when  the  latter  is  melted,  the  molten  metal  is  poured  in  until  it  is  up  to  and  running 
over  the  level  of  the  outside  sand  all  round.  The  dross  is  then  skimmed  off  and  the 
metal  is  left  to  cool,  as  it  shrinks  equally  all  over  and  requires  no  further  attention. 
It  is  obvious  that  instead  of  making  the  bottom  by  pouring  on  molten  metal,  a  piece  of 
the  required  size  can  be  cut  out  of  thinner  sheet  lead,  and  placed  on  the  top  of  the 
inside  sand  ;  but  the  majority  of  experienced  workmen  prefer  the  first-mentioned  method 
of  burning  in  a  bottom.  If  the  article  is  of  considerable  size,  however,  it  is  necessary 
to  have  more  than  one  workman,  as  the  metal  must  be  poured  on  as  quickly  as  possible.  ' 

This  method  of  lead-burning  is  considerably  troublesome,  and  is  rarely  used,  except 
when  the  lead  is  too  thick  to  be  melted  conveniently  by  means  of  the  blowpipe,  or  the 
oxyhydrogen  flame.  The  latter  is,  however,  always  used  when  possible  by  those  who 
can  accomplish  the  operation,  which  requires  a  much  greater  degree  of  skill  than  the 
process  described  above. 

Similar  processes  are  applicable  in  the  case  of  the  other  metals.  Thus  brass  may  be 
burned  together  by  placing  the  parts  to  be  joined  in  a  sand  mould,  and  pouring  a 
quantity  of  molten  brass  on  them,  afterwards  reducing  the  parts  by  means  of  the  file, 
&c.,  to  proper  dimensions.  The  sine  qua  non  is  plenty  of  molten  metal,  made  a 
trifle  hotter  than  usual.  Pewter  is  generally  "  burned "  by  the  blowpipe  or  a  very 
hot  copper-bit.  In  angles,  where  bent  over  sharp  comers,  and  in  seams,  one  edge  is 
allowed  to  stand  over  the  surface  of  the  other,  and  a  strip  of  the  same  metal  is  then 
laid  along  the  intended  junction.  This  joint  is  burned,  as  mentioned,  by  melting  the 
surfaces  and  edges  by  means  of  a  blowpipe  or  the  hot  soldering-iron,  and  the  super- 
fluous metal  is  filed  off,  leaving  the  joint,  if  at  an  angle,  looking  as  if  it  had  been 
made  out  of  the  solid.  The  principle  of  the  process  is  the  same  whatever  be  the  mode 
in  which  it  is  performed ;  and  when  hot  metal  is  used  as  the  sole  agent  of  heat,  it  is 
necessary  to  have  plenty  of  it,  and  to  see  that  the  parts  to  be"  joined  are  clean.  It  is 
scarcely  necessary  to  say  that  the  autogenous  method  is  the  only  proper  method  of 
remedying  the  defects  in  castings,  and  notwithstanding  the  trouble  attached  to  it, 
should  always  be  attempted  with  all  metals  for  which  it  is  applicable,  and  all  articles 
in  which  it  is  possible.  It  is  not  to  be  supposed  that  trifling  defects  in  iron  castings 
will  be  remedied  by  this  means,  though  there  is  no  very  great  difficulty  in  accomplishing 
it,  as  flanges  are  often  burned  on  to  pipes  and  wheels,  but  with  the  more  costly  or  easily 
worked  metals,  the  practice  of  this  process  would  be  attended  with  advantage. 

Dr.  Hoffman  suggests  endeavours  being  made  to  employ  the  oxyhydrogen  flame  for 
effecting  autogenous  joints  in  all  metals.  The  operation  is  already  conducted  with 
complete  success  in  the  case  of  2  essentially  different  metals,  lead  and  platinum,  and 
offers  the  advantages  of  being  cleaner,  stronger,  and  more  economical  of  time  and 
materials. 


Soldering — Burnm^. 


95 


For  all  leaden  vessels  and  chambers  to  be  used  in  contact  witli  acid  vapours  or  liquids, 
autogenous  soldering  is  the  only  admissible  way  of  making  a  joint.  Tho  apparatus 
employed  consists  of  a  hydrogen  gas  generator,  or  "  burning  machine,"  as  it  is  conmionly 
called,  an  "air  vessel  "  or  portable  bellows,  some  indiarubber  tubing,  and  a  set  of  o-as- 
cocks  and  jets.  The  hydrogen  generator  is  shown  in  Fig.  148  :  a  is  an  airtight  leaden 
cistern,  having  a  perforated  shelf  h,  and  an  opening  c  in  the  top;  d  is  another  leaden 
cistern  with  a  perforated  shelf  e.    A  pipe /connects  the  cisterns  a  d,  passing  through  a 


us. 


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ijuiy 


as  far  as  the  shelf  h,  which  it  just  perforates.  The  hinged  cover  g  being  turned  back, 
the  cistern  a  is  filled  with  sheet  zinc  cuttings,  and  the  cover  is  closed.  Diluted  oil  of 
vitriol,  say  1  qt.  of  the  acid  to  1  gal.  water,  is  poured  into  the  cistern  d,  and  finds  its 
way  through  the  pipe /into  the  bottom  of  the  cistern  a,  rising  through  the  strainer  h, 
and  surrounding  the  zinc.    The  acid  acts  upon  the  zinc,  forming  zinc  suli^hate,  with 


96 


Soldering — Burning. 


consequent  liberation  of  hydrogen.  As  the  hydrogen  gas  is  set  free,  it  passes  through  the 
cock  and  pipe  h  into  the  leaden  vessel  i,  partially  filled  -with  water,  and,  passing  through 
the  water,  it  becomes  purified,  and  escapes  at  the  pipe  h  ;  m  is  the  pipe  through  which 
the  generator  is  emptied  of  acid  when  the  gas  is  no  longer  required.  The  vessel  i  may 
be  removed  from  its  place  by  unscrewing  the  nut  close  to  the  cock  on  the  pipe  7t,  and 


149. 


151. 


j^y,kkXm?U  ■Vl'l'-r^^rTTTvi     ^ 


rS 


TOP  VIEW 


150. 


may  be  filled  with  water  or  emptied  through  the  pipe  n.  The  pipes 
m  and  n  are  plugged  with  corks ;  o  are  short  pieces  of  pipe  supporting 
the  shelf  6,  to  which  they  are  attached. 

The  air  vessel  consists  simply  of  a  wooden  cask  open  at  the  top, 
containing  a  cylinder  of  zinc,  with  a  closed  top,  having  a  hole  and 
cover  in  the  centre,  as  shown  in  Fig.  149,  which  is  drawn  on  a  scale 
of  ^  in.  =  1  ft.  The  cask  a  is  partially  filled  with  water,  the  cover  h  \p5»* 
(which  is  coated  underneath  with  sheet  indiarubber  to  make  it  shut 
close)  is  opened,  the  cylinder  c  is  raised,  and  the  cover  is  closed  agiain,  preventing  th& 
escape  of  air  from  the  cylinder  except  through  the  small  pipe  d.  A  weight  e  is  placed! 
on  the  top  of  the  cylinder,  to  keep  the  cover  h  firmly  closed,  aud  give  force  to  the 
current  of  air  issuing  from  d,  the  weight  being  conveniently  represented  by  a  J-,  J-,  or 
1-cwt.,  according  to  the  pressure  of  air  required. 


Soldering — Cold;  Hard.  97 

A  small  bellows,  Fig.  150,  is  sometimes  used  by  plumbers  for  obtaining  a  supply  of 
air.  It  is  more  portable  than  the  air  vessel,  but  cannot  bo  usl(1  without  an  assistant  to 
work  .it. 

ludiarubber  tubes  o  h  (Fig.  151)  connect  the  gas  generator  and  air  vessel  or  bellows 
with  a  pail  of  brass  cocks  and  breeches-pipe  c.  Tlie  gas  aTul  air,  being  admitted  tlirouf  li 
these  cocks,  unite  in  the  tube  d,  and,  pnssing  through  the  brass  i)ipe  e  and  jet/,  may  bo 
ignited,  and  produce  an  intensely  hot  flame,  by  which  leaden  sheets  may  be  joined 
without  the  aid  of  any  flux. 

The  lead  to  be  burned  must  first  be  scraped  bright,  and  where  a  strong  seam  is  required 
as  for  instance  in  the  bottoms  of  chambers,  strips  of  clean  lead  are  run  on  in  the  manner 
(if  solder.  But  it  is  essential  to  success  that  all  the  surfaces  to  be  subjected  to  the  flame 
be  bright  and  dry,  and  that  no  moisture  be  sufticiently  near  the  seam  to  be  drawn  into  it 
by  the  heat.  Several  jets  are  in  use,  with  holes  of  various  sizes,  for  procuring  a  laro'e  or 
small  flame,  according  to  the  special  requirements  of  the  work  in  hand ;  and  the  intensity 
of  the  heat  is  also  regulated  by  the  proportions  and  quantities  of  gas  and  air  admitted 
through  the  cocks.  As  it  is  imperative  that  the  flame  should  not  be  subject  to  sudden 
variation,  little  brass  tubes  are  fitted  to  the  nozzle  to  guard  the  flame  from  air  currents, 
when  working  out  of  doors  or  in  draughty  places.     (Lock's  '  Sulphuric  Acid,') 

Cold  Soldering. — Various  nostrums  have  been  proposed  from  time  to  time  which 
profess  to  be  reliable  methods  of  soldering  without  heat ;  but  when  tried,  they  have 
geuerally  proved  useless.  The  following  recipe,  which  is  due  to  Fletcher,  of  Warring- 
ton, will  be  found  to  bo  more  trustworthy.  It  must  be  borne  in  mind  that,  though  the 
first  preparation  is  tedious,  a  large  quantity  of  the  materials  can  be  made  at  once,  and  the 
actual  soldering  process  is  as  simple  and  quick  as  it  well  can  be. 

Flux :  1  part  metallic  sodium  to  50  or  CO  of  mercury.  These  combine  on  being  wel\ 
shaken  in  a  bottle.  If  this  is  too  much  trouble,  the  sodium  amalgam  can  be  bought,  ready 
made,  from  any  chemist  or  dealer  in  reagents.  This  sodium  amalgam  must  be  kept  in  a 
stoppered  bottle  closed  from  the  air.  It  has  the  projjerty  of  amalgamating  (equivalent 
to  tinning  by  heat)  any  metallic  surface,  cast  iron  included. 

Solder :  Make  a  weak  solution  of  copper  sulphate,  about  1  oz,  to  1  qt.  of  water. 
Precipitate  the  copper  by  rods  of  zinc ;  wash  the  precipit;ite  2  or  3  times  with  hot  water  ; 
drain  the  water  off,  and  add,  for  every  3  oz.  of  precipitate,  6  oz.  or  7  oz.  mercury  ;  add 
also  a  little  sulphuric  acid  to  assist  the  combination  of  the  2  metals.  When  combined, 
they  form  a  paste  which  sets  intensely  hard  in  a  few  hours,  and  this  paste  should  be 
made,  whilst  soft,  into  small  pellets. 

When  wanted  for  use,  heat  one  or  more  of  the  pellets  until  the  mercury  oozes  out 
from  the  surface  in  small  beads  ;  shake  or  wipe  them  ofl",  and  rub  the'  pellet  into  a  sofl 
paste  with  a  small  mortar  and  pestle,  or  by  any  other  convenient  means,  until  it  is  as 
smooth  and  soft  as  painters'  white-lead.  This,  when  put  on  a  surface  previously  amal- 
gamated by  the  sodium  and  mercury,  adheres  firmly,  and  sets  perfectly  hard  in  about  3 
hours.  The  joint  can  be  parted,  if  necessary,  either  by  a  hammer  and  cold  chisel,  or  by 
a  heat  about  sufficient  to  melt  plumbers'  solder. 

Hard  Soldering.— Hard  soldering  is  the  art  of  soldering  or  uniting  2  metals  or  2 
pieces  of  the  same  metal  together  by  means  of  solder  that  is  almost  as  hard  and  infusible 
as  the  metals  to  be  united.  In  some  cases,  the  metals  to  be  united  are  heated  to  a  high 
degree,  and  their  surfaces  simply  united  without  solder  by  means  of  fluxing  them.  This 
process  is  then  termed  brazing,  and  some  of  the  hard  soldering  processes  are  also  oftea 
termed  brazing  ;  both  brazing  and  hard  soldering  are  usually  done  in  the  open  fire  on 
the  braziers'  hearth.  When  soldering  work  of  copper,  iron,  brass,  &c.,  the  solder 
generally  used  is  a  fusible  brass,  and  the  work  to  be  soldered  is  prepared  by  filing  or 
scraping  perfectly  clean  the  edges  or  parts  to  be  united.  The  joints  are  then  put  in 
proper  position,  and  bound  securely  together  with  binding  wire  or  clamps ;  the  gnmu- 
lated  solder  and  powdered  boras  are  mixed  in  a  cup  with  a  very  little  water,  and  spread 

u 


98  SoLDEKiNQ — Hard. 

along  the  joint  to  be  united  with  a  strip  of  sheet  metal  or  a  small  spoon.  The  work  is 
then  placed  upon  a  clear  fii'e,  and  heated  gradually  to  evaporate  the  water  used  in 
uniting  the  solder  and  borax,  and  also  to  drive  off  the  water  contained  in  the  crystallized 
borax,  which  causes  the  borax  to  boil  up  with  an  appearance  of  froth.  If  the  work  is 
heated  hastily,  the  boiling  of  the  borax  may  displace  the  solder,  and  for  this  reason  it  is 
better  to  roast  or  boil  the  borax  before  mixing  with  the  solder.  When  the  borax  ceases 
to  boil,  the  heat  is  increased  ;  and  when  the  metal  becomes  a  faint  red,  the  borax  fuses 
quietly,  like  glass,  and  shortly  after,  as  the  heat  of  the  metal  is  increased  to  a  bright  red, 
the  solder  also  fuses,  which  is  indicated  by  a  small  blue  flame  from  the  burning  of  the 
zinc.  Just  at  this  time  the  work  should  be  jarred  slightly  by  being  tapped  lightly  with 
the  poker  or  hammer,  to  put  the  solder  in  vibration  and  cause  it  to  run  into  the  joint. 
For  some  work  it  is  not  necessary  to  tap  it  with  the  poker,  for  the  solder  is  absorbed 
into  the  joint  and  nearly  disappears  without  tajiping.  In  order  to  do  good  work,  it  is 
necessary  to  apply  the  heat  as  uniformly  as  possible,  so  as  to  have  the  solder  melt 
uniformly.  This  is  done  by  moving  the  work  about  in  the  fire.  As  soon  as  the  work 
has  been  properly  heated,  and  the  solder  has  flushed,  the  work  should  be  removed 
from  the  fire,  and,  after  the  solder  has  set,  it  may  be  cooled  in  cold  water  without 
injury. 

Tubes  to  be  soldered  are  generally  secured  by  binding  wire  twisted  together  around 
the  tube  with  the  pliers.  All  tubes  that  are  soldered  upon  the  open  fire  are  soldered  from 
within,  for  if  they  were  soldered  from  the  outside  the  heat  would  have  to  be  trans- 
mitted across  the  tube  with  greater  risk  of  melting  the  lower  part  of  the  tube,  the  air  in 
the  tube  being  a  bad  conductor  of  heat ;  and  it  is  necessary  that  both  ends  of  the  tube 
should  be  open,  so  as  to  watch  for  the  melting  of  the  solder.  lu  soldering  long  tubes, 
the  work  rests  upon  the  flat  plate  of  the  braziers'  hearth,  and  portions  equal  to  the 
length  of  the  fire  are  soldered  in  succession.  The  common  tubes  or  gas-pipes  are 
soldered  or  welded  from  the  outside.  This  is  done  by  heating  the  tube  in  a  long  air 
furnace,  completely  surrounded  by  hot  air,  by  which  means  the  tube  is  heated  more 
uniformly  than  in  the  open  fire.  After  the  tubes  have  been  heated  to  the  welding  heat, 
they  are  taken  out  of  the  furnace,  and  drawn  through  clamps  or  tongs  to  unite 
the  edges,  and  are  then  run  through  grooved  rollers  2  or  3  times,  and  the  process  is 
complete.  The  soldering  or  welding  of  iron  tubes  requires  much  less  precaution  in 
point  of  the  heat  than  some  of  the  other  metals  or  alloys,  for  there  is  little  or  no  risk  of 
fusing  it. 

In  soldering  light  ironwork,  such  as  locks,  hinges,  &c.,  the  work  is  usually  covered 
with  a  thin  coating  of  loam  to  j^revent  the  iron  from  being  scaled  off  by  the  heat. 
Sheet  iron  may  be  soldered  at  a  cherry-red  heat  by  using  iron  filings  and  pulverized 
borax  as  a  solder  and  flux.  The  solder  and  flux  are  laid  between  the  irons  to  be 
soldered,  and  the  whole  is  bound  together  with  binding  wire,  heated  to  redness,  taken 
from  the  fire,  and  laid  upon  the  anvil ;  the  2  irons  are  united  by  a  stroke  upon  the  set 
hammer.  Steel  or  heavy  iron  may  be  united  in  the  same  way  at  a  very  low  heat.  For 
soldering  iron,  steel,  and  other  light-coloured  metals,  as  well  as  brasswork  that  requires 
to  be  very  neatly  done,  the  silver  solder  is  generally  used  on  account  of  its  superior 
fusibility  and  combining  so  well  with  most  metals,  without  gnawing  or  eating  away 
the  sharp  edges  of  the  joints.  Silver  solder  is  used  a  great  deal  in  the  arts,  and  from 
the  sparing  or  careful  way  in  which  it  is  used,  most  work  requires  little  or  no  finish  after 
soldering,  so  that  the  silver  solder,  although  expensive,  is  in  reality  the  cheapest  solder  in 
the  long  run.  For  silver  soldering,  the  solder  is  rolled  into  thin  sheets  and  then  cut 
into  narrow  strips  with  the  shears.  The  joints  or  edges  to  be  united  are  first  coated  with 
pulverized  borax,  which  has  been  previously  heated  or  boiled  to  drive  off  the  water  of 
crystallization.  The  small  strips  of  solder  are  tlien  placed  with  forceps  upon  the  edges 
or  joints  to  be  united,  and  the  work  is  heated  upon  the  braziers'  hearth.  The  process  of 
silver  soldering  upon  the  larger  scale  is  essentially  the  same  as  the  operation  of  brazing. 


Soldering — Soft.  09 

For  hard  solJerius:  small  work,  such  as  drawing  instruments,  jewellery,  buttons,  &c.,  tlio 
blowpipe  is  almost  exclusively  used,  and  the  solder  employed  is  of  the  finest  or  best 
quality,  such  as  gold  or  silver  solder,  which  is  always  drawn  into  thin  sheets  of  very  fino 
wire,  and  it  is  sometimes  pulverized  or  granulated  by  fding  ;  but  if  solder  is  pulverized 
very  fine,  a  greater  degree  of  heat  is  required  to  fuse  a  minute  particle  of  metal  than 
to  fuse  a  large  piece. 

In  soldering  jewellery,  the  jeweller  usually  applies  the  borax  or  other  flux  in  solution 
with  a  very  small  camel-hair  brush.  The  solder  is  rolled  into  very  thin  sheets  and  then 
clipped  into  minute  particles  of  any  desired  shape  or  size,  which  are  so  delicately  applied 
to  the  work  that  it  is  not  necessary  to  file  or  scrape  off  any  portion  of  them,  none  bein"- 
in  excess.  The  borax  or  other  flux  nsed  in  the  operation  is  removed  by  rubbing  the  work 
with  a  rag  that  has  been  moistened  with  water  or  dilute  acids. 

Soft  Soldering. — Soft  soldering  is  the  art  of  soldering  or  uniting  2  of  tlie  fusil)le 
metals  or  2  pieces  of  the  same  metal.  The  solder  used  is  a  more  soft  and  fusiljle  alloy 
than  the  metals  united,  and  the  mode  of  applying  the  heat  is  consequently  different  from 
that  employed  in  hard  soldering.  The  soft  solders  are  prepared  in  different  forms  to  suit 
the  different  'classes  of  work  for  which  they  are  intended.  Thus  for  tin  soldering,  the 
solder  is  cast  into  bars  of  10  or  12  in.  long  by  1  in.  wide,  and  by  some  it  is  cast  into 
cakes  10  or  12  in.  long  by  3  or  4  in.  wide.  Plumbers'  solder  is  generally  cast  into  small 
ingots  or  cakes,  2  in.  square  or  more,  according  to  the  work  for  which  they  are  intended, 
and  size  of  pot  they  are  to  bo  melted  in.  Some  of  the  very  fusible  solders  that  are 
destined  for  very  light  work  are  trailed  from  the  ladle  upon  an  iron  plate,  so  as  to  draw 
the  solder  into  thin  or  large  bars,  so  that  the  size  of  the  solder  may  always  suit  the  work 
tliat  it  is  used  upon. 

In  soft  soldering,  it  is  very  essential  that  the  parts  to  be  united  should  be  perfectly 
clean  and  free  from  metallic  oxides,  and  for  this  reason  they  are  generally  wet  with  a 
little  zinc  chloride  before  applying  the  solder ;  and  when  the  metal  is  old  or  very  dirty, 
it  must  be  scraped  on  the  edges  intended  to  be  united  before  applying  the  solder. 
When  soldering  leaden  pipe,  sheet  lead,  &c.,  the  plumber  first  smears  a  mixture  of  size 
and  lampblack  around  the  intended  joint  to  prevent  the  melted  solder  adhering  to  the 
metal  at  the  point  where  it  is  not  wanted.  The  parts  to  be  united  are  then  scraped 
quite  clean  with  the  shave-hook,  and  the  clean  metal  is  rubbed  over  with  tallow.  The 
wiped  joints  are  usually  made  without  using  the  soldering-iron.  The  solder  is  heated 
in  the  plumbers'  pot  rather  beyond  its  melting-point,  and  poured  plentifully  upon  the 
joint  to  heat  it.  The  solder  is  then  moulded  into  the  proper  shape,  and  smoothed  with 
cloth  or  several  folds  of  thick  bed-ticking,  which  is  well  greased  to  prevent  burning, 
and  the  surplus  solder  is  removed  by  the  cloth.  In  forming  the  striped  joint,  the 
soldering-iron  and  cloth  are  both  used  at  the  commencement  in  moulding  the  solder  and 
heating  the  joint.  Less  solder  is  poured  on  when  forming  this  joint  than  when  forming 
the  wiped  joint,  and  a  smaller  quantity  remains  upon  the  work.  Striped  joints  are  not 
so  neat  in  appearance  as  wiped  joints,  but  they  are  often  claimed  to  be  sounder,  from 
the  solder  having  been  left  undisturbed  when  in  the  act  of  cooling ;  but  in  wiped  joints, 
the  body  of  solder  is  heavier,  and  the  shrinkage  of  it  around  the  pipe  is  suiBcient  to 
unite  with  the  pipe.  In  forming  joints  in  leaden  pipe^the  cloth  is  always  used  to  support 
the  fluid  solder  when  poured  on  the  pipe. 

Light  leadwork  that  requires  more  neatness  than  the  ordinary  plumbing  is  usually 
soldered  with  the  common  tinners'  soldering-iron.  This  is  made  of  a  square  piece  of 
copper  weighing  3  or  4:  oz.  to  3  or  4  lb.,  according  to  the  size  of  the  work  it  is  intended 
for.  This  piece  of  copper  is  drawn  down  to  a  long  square  point,  or  to  a  flat  wedge,  and  is 
riveted  into  an  iron  shank  fitted  to  a  wooden  handle.  The  copper  bit  or  soldermg-iroi; 
is  then  heated  in  the  tinners'  firepot  with  charcoal  to  dull  redness,  and  is  then  screwed 
in  the  vice  and  hastily  filed  to  a  clean  metallic  surface.  It  is  next  rubbed  with  a  piece 
of  sal-ammoniac,  or  on  some  powdered  rosin,  and  then  upon  a  few  drops  of  solder  in  the 

H  2 


100  Soldering — Soft. 

bottom  of  the  soldering-pan.  In  tiiis  way  tlie  soldering-iron  is  thoroughly  coated  ■with 
tin,  and  is  then  ready  fur  use.  In  soldering  tin-plate  work,  the  edges  are  slightly 
lapped  over  each  other,  and  the  joint  or  seam  is  strewed  with  powdered  rosin,  which  is 
usually  contained  in  a  small  hox  set  in  tlie  soldering-pan.  Tlie  soldering-iron,  wliich 
has  been  heated  in  the  tirepot,  is  then  drawn  over  the  cake  of  solder ;  a  few  drops 
are  melted  and  adhere  to  the  soldering-iron,  and  are  distributed  by  it  along  the  joint  or 
seam.  In  large  work,  the  seams  are  first  tacked  together,  or  united  by  drops  of  solder 
EO  as  to  hold  the  seams  in  proper  position  while  being  soldered ;  but  this  is  seldom 
done  in  small  work,  which  can  be  easily  held  together  with  the  hands.  Two  soldering 
tools  are  generally  employed,  so  that  while  one  is  being  used  for  soldering,  the  other  is 
being  reheated  in  the  firepot,  thus  avoiding  the  delay  of  waiting  for  the  tool  to  heat. 
The  temperature  of  the  tool  is  very  important :  if  it  is  not  hot  enough  to  melt  the  solder, 
it  must  be  returned  to  the  fire ;  and  if  it  gets  too  hot,  the  tinning  will  be  burnt  oft", 
the  solder  will  not  hang  to  it,  and  the  tool  must  be  retinned  before  it  can  be  used.  In 
soldering  tinware,  the  tool  is  usually  passed  only  once  over  the  work,  being  guided 
by  the  contact  with  the  fold  or  ledge  of  the  seam ;  but  when  the  operator  is  not  an 
expert,  he  usually  runs  the  tool  backward  and  forward  over  the  work  2  or  3  times.  This 
makes  slow  work. 

Sheet  copper,  in  common  work,  is  soldered  with  the  soldering-iron  in  the  same 
manner  as  sheet  tin  ;  but  the  finer  or  more  important  work  is  brazed  or  hard  soldered. 
In  soft  soldering  copper,  as  well  as  sheet  iron,  the  flux  generally  used  is  powdered 
sal-ammoniac,  or  a  solution  of  sal-ammoniac  and  water.  A  piece  of  cane,  the  end  of 
which  is  split  into  filaments  to  make  a  stubby  brush,  is  used  for  laying  the  solution  on 
the  work,  and  powdered  rosin  is  subsequently  applied.  Some  workmen  mix  the  powdered 
sal-ammoniac  and  rosin  together  before  applying  it  to  the  work.  This  they  claim  u 
better  than  putting  them  on  separately ;  but  so  long  as  the  metals  are  w^ell  defended 
from  oxidation,  either  of  the  modes  is  equally  good,  for  the  general  principle  is  the 
same  in  both.  Zinc  is  the  most  difficult  metal  to  solder,  and  the  joints  or  seams  are 
seldom  so  neatly  formed  as  in  tin  or  copper.  Zinc  will  remove  the  coating  of  tin  from 
the  soldering  tool  in  a  very  short  time.  This  arises  from  the  superior  afl^inity  of  copper 
for  zinc  than  for  tin,  and  the  surface  of  the  tool  is  freed  from  tin,  and  is  coated  with 
zinc.  Sal-ammoniac  is  sometimes  used  for  a  flux  in  soldering  zinc,  but  the  most 
common  flux  employed  for  zinc  is  zinc  chloride,  which  is  made  by  dissolving  fragments 
of  zinc  in  hydrochloric  acid  diluted  with  about  an  equal  amount  of  water.  This  solution 
is  put  in  a  wide-mouthed  bottle,  and  small  strips  of  zinc  are  dropped  into  it  imtil 
they  cease  to  be  dissolved.  The  solution  is  then  ready  for  use ;  it  is  likewise  resorted 
to  for  almost  all  the  other  metals,  as  it  can  be  employed  without  such  strict  necessity 
for  clean  surfaces  as  when  some  of  the  other  fluxes  are  availed  of. 

In  soft  soldering,  the  soldering-iron  is  only  used  for  thin  sheet  metals,  because, 
in  order  to  unite  2  metals  by  soldering,  their  temperature  must  be  raised  to  the  melting- 
point  of  the  solder,  and  a  heavy  body  of  metal  cannot  be  sufiiciently  heated  with  the 
soldering-iron  without  making  the  latter  too  hot,  which  is  apt  to  burn  off  the  coating 
of  tin,  or  to  cause  it  to  be  absorbed  by  the  copper,  as  in  superficial  alloying,  and  the  solder 
will  not  adhere  to  the  tool,  and  cannot  be  spread  along  the  joint  by  it.  In  soft  soldering 
heavy  work,  the  work  is  first  filed  or  scraped  perfectly  clean  at  the  points  to  be  soldered,  and 
is  dipped  into  a  bath  of  liquid  solder,  which  is  covered  with  a  little  melted  sal-ammoniac 
to  prevent  oxidation,  and  also  to  act  as  a  flux  for  uniting  the  metals.  In  dipping 
the  work  into  tiie  bath,  it  flrst  comes  into  contact  with  the  flux,  and  is  coated  by  it 
before  it  is  subjected  to  the  heat ;  when  dipped  into  the  solder,  the  tin  readily  adheres 
to  it ;  and  after  heavy  pieces  of  metal  have  been  tinned  in  this  way,  or  by  the  process  of 
dry-tinning  with  mercury,  they  may  be  soldered  with  the  soldering-iron.  "When  tinning 
thin  pieces  of  brass  or  copper  alloys  for  soldering,  it  is  usually  done  by  rubbing  a  few 
drops  of  solder  over  the  part  to  be  tinned  with  the  soldering-iron ;  and  if  tinned  by 


•  Soldering — Soft.  101 

dipping  into  a  bath,  it  must  be  quickly  dipped,  or  tlicrc  is  a  risk  of  tlio  Ihin  shcest  being 
melted  by  the  solder.  "When  tinning  iron  or  steel,  the  work  must  be  allowed  to  remain 
in  the  bath,  for  some  time,  so  as  to  be  thorouirhly  heated  bj-  the  bath,  or  the  tin  will 
not  be  completely  muted  to  the  iron  or  steel,  and  may  peel  off  when  cold.  Large  itieces 
of  iron  or  steel  that  are  inconvenient  to  dip  into  a  bath  are  tinned  by  heatin"-  in  an 
open  fire,  and  rubbing  the  solder  on  w  ith  tlie  soldering-iron,  using  cither  sal-ammoniao 
or  rosin  as  a  flux.  When  tinning  in  this  way,  the  lowest  heat  that  will  fuse  the  solder 
should  be  used. 

Hard  solder  differs  from  soft  solder  in  tliat  the  "  hard  "  ia  an  alloy  of  silver  and  brass 
■while  the  "  soft"  is  of  bismuth,  lead,  &c. ;  the  mode  of  working  differs  also.  "With  hard 
solder,  an  intense  and  glowing  heat  is  absolutely  necessary  to  cause  fusion  of  the  metals, 
but  \^ith  soft  solder  a  comparatively  low  heat  will  suffice.  It  must  be  evident  that  by 
the  former  mode,  where  fusion  takes  place,  there  is  a  more  complete  union  made  than 
by  the  latter,  where  there  is  little  more  than  cohesion.  The  latter  mode  of  repairing- 
has,  however,  these  advantages,  that  as  many  articles  are  built  up,  so  to  speak,  of  pieces, 
and  in  such  ways  that  only  experienced  workmen  can  handle  them  satisfactorily,  the 
amateur  may  attempt  repairing  them  with  greater  confidence  and  assurance  of  success 
and  he  has  no  need  to  provide  himself  with  a  variety  of  chemicals,  for  the  purpose  of 
restoring  the  colour  to  the  article  that  has  been  rendered  unsightly  by  the  heat.  Apart 
from  these  advantages  there  are  others,  as  soft  soldering  may  be  accomplished  by  the 
blowpipe,  the  soldering  "  bit,"  or  actual  contact  with  the  flame.  Preference  is  given  to 
one  method  by  one  worker,  to  another  by  another;  no  absolute  rule  can  be  laid  down; 
all  three  modes  can  be  used  as  the  necessities  of  the  work  in  hand  may  require. 
Eosin,  sal-ammoniac,  solution  of  hydrochloric  acid  and  zinc,  and  in  some  cases  fats,  are 
used  as  a  flux.  Generally  speaking,  hydrochloric  acid  (spirits  of  salts)  killed  by  zinc  will 
answer  all  purposes  :  to  make  the  solution,  procure  a  pennyworth  of  spirits  of  salts,  and 
place  it  in  an  open  glass  or  glazed  earthenware  vessel ;  and  having  a  number  of  small 
pieces  of  zinc,  throw  in  a  few.  As  they  become  consumed,  throw  in  more  until  all 
chemical  action  has  ceased.  So  soon  as  the  zinc  is  put  in,  a  violent  action  commences, 
and  it  is  well  to  set  the  vessel  down,  as  it  becomes  intensely  hot,  and  emits  a  pungent 
vapour  which  it  is  wise  not  to  inhale.  When  all  turbulence  has  ceased,  strain  off  the 
clear  liquid  and  add  twice  its  quantity  of  clear  water,  decanting  all  into  a  stoppered 
or  well-corked  bottle.  A  piece  or  two  of  zinc  may  be  dropped  in  to  kill  any  remaining 
salts.  A  soldering  bit  may  be  made  by  taking  a  piece  of  stout  brass  wire,  say,  rather 
thinner  than  a  common  wood  penholder,  and  about  G  in.  long,  and  hammering  one 
end  into  the  form  of  an  abrupt  spear-point ;  inserting  the  other  into  a  wooden  handle. 
Solder  of  a  pure  and  easy-flowing  kind  should  be  procured ;  preference  being  given 
to  that  sold  by  dealers  in  jewellers'  requisites.  A  pair  of  tweezers  or  long  slender 
pliers  should  alsQ  be  got.  Armed  with  these,  no  fear  of  burnt  fingers  need  be 
entertained. 

As  an  example  to  illustrate  the  operation,  we  may  take  the  movable  top  of  a  silver- 
plated  candlestick.  It  often  happens  that  a  too-low  burning  candle  mt-lts  the  solder 
away  from  the  connections.  To  repair  this,  carefully  remove  all  dirt  and  grease  from 
the  parts  in  contact,  and  scrape  them  bright  with  a  knife  or  other  tool.  Then  take 
the  '•  bit"  and  file  the  end  clean  ;  dip  it  in  the  zinc  solution,  and,  holding  the  afterpart 
in  the  gas  flame,  run  a  little  solder  all  over  the  tip  to  "  tin  "  it.  Next,  run  a  bead  of 
solder  on  the  end ;  then,  taking  either  part  of  the  broken  top  in  the  tweezers,  apply, 
by  means  of  a  peg  or  piece  of  brass  wire,  a  little  of  the  solution  to  the  part  where 
the  solder  is  required.  Proceed  to  warm  the  metal  top  in  the  edge  of  the  flame,  at  the 
same  time  holding  the  "  bit "  obliquely  in  the  gas  and  in  contact  with  the  top.  The 
solder  will  quickly  melt,  and  attach  to  it,  and  whilst  in  a  molten  state  must  be  thinly 
distributed  all  roimd  on  that  part  only  which  has  to  be  connected  with  the  socket. 
This  has  to  be  "  tinned  "  in  the  same  way.     This  done,  lay  aside  the  "  bit'  and  take  the 


102  Soldering — Soft. 

blowpipe.  Holding  the  top  inverted,  place  the  socket  in  its  position,  and  after  putting 
a  little  more  solution  to  the  parts,  direct  a  small  flame  all  round  the  joint,  turning  the 
article  about  to  do  this.  If  the  top  has  an  ornamental  filled  edge  to  it,  keei)  the  heat 
as  much  as  possible  away  from  that  part,  or  the  filling,  which  is  only  lead  or  solder, 
will  run  out.  A  sufficient  heat  having  been  got,  the  solder,  at  the  points  of  contact, 
will  melt  and  run  together.  When  it  lias  run  all  round,  press  the  socket  gently  down, 
and  hold  until  the  solder  is  seen  to  "set,"  and  the  union  is  then  completed.  Cool, 
and  swill  in  water.  If  there  is  an  excess  of  solder,  and  it  has  run  out  into  a  bead,  a 
sharp  knife-edge  will  detach  it,  and  an  oiled  leather  buff"  will  remove  the  stain.  A 
little  cleaning  with  rouge  will  finish  the  work.  Experience  only  in  these  matters  teaches 
one  how  much  or  how  little  solder  is  required :  use  too  little  rather  than  too  much  at 
first.  Do  not  let  the  solution  spatter  upon,  or  come  in  contact  with,  or  vaporize  near  to 
steel  tools,  or  they  will  soon  have  a  coating  of  rust  upon  them. 

Generalities. — (a)  Apparatus.  Blowpipes  and  Lamps. — The  blowpipe  and  an 
alcohol  lamp  are  largely  used  in  hard  soldering,  temi^ering  small  tools,  and  by  chemists 
and  mineralogists  as  an  important  means  of  analysis,  &c.,  and  for  these  uses  the 
blowjiipe  has  received  very  great  attention,  both  from  mechanics  and  distinguished 
philosophers.  Most  of  the  small  blowpipes  are  supplied  with  air  from  the  lungs  of  the 
operator,  and  the  larger  ones,  or  where  they  are  brought  into  general  use,  are  supplied 
v/ith  air  from  a  bellows  moved  with  the  foot,  or  from  a  vessel  in  which  the  air  has  been 
condensed  by  a  syringe,  or  from  a  small  rotary  fan.  The  ordinary  blowpipe  is  a  light 
brass  or  tin  tube  about  10  or  12  in.  long,  and  |  to  J  in.  in  diameter  at  the  end  for  the 
mouth  and  j\j  in.  or  less  at  the  jet  end.  The  small  end  is  slightly  curved,  so  that  the 
flame  may  be  thrown  immediately  imder  the  observation  of  the  operator.  There  are 
several  other  kinds  of  blowpipe  for  the  mouth,  which  are  fitted  with  various  contrivances, 
such  as  a  series  of  apertures  of  difierent  diameters,  joints  for  portability  and  for  placing 
the  jet  at  difi'erent  angles,  and  with  a  ball  for  collecting  the  condensed  vapour  from 
the  lungs ;  but  none  of  these  is  in  common  use.  The  blowpipe  may  be  supplied  with 
air  from  the  lungs  with  much  more  effect  than  might  be  expected,  and,  with  a  little 
practice,  a  constant  stream  can  be  maintained  for  several  minutes  if  the  cheeks  of  the 
operator  are  kept  fully  distended  with  wind,  so  that  their  elasticity  alone  will  serve  to 
impel  a  part  of  the  air,  while  the  ordinary  breathing  is  carried  on  through  tlie  nostrils 
for  a  fresh  supply. 

The  heat  created  by  the  blowpipe  is  so  intense  that  fragments  of  almost  all  the 
metals  may  be  melted  when  they  are  supported  upon  charcoal,  with  the  heat  from  a 
common  tallow  or  wax  candle.  The  most  intense  heat  from  the  blowpipe  is  the  pointed 
flame,  and  the  hottest  part  of  the  flame  is  the  extreme  jDoint  of  the  inner  or  blue  flame. 
Large  particles  of  ore  or  metals  that  require  less  heat  are  held  somewhat  nearer  to  the 
candle  or  lamp,  so  as  to  receive  a  greater  portion  of  the  flame,  and  when  a  very  mild 
degree  of  heat  is  wanted  on  a  small  piece  of  metal  it  is  held  farther  away.  By  thus 
increasing  or  decreasing  the  distance  between  the  candle  or  lamp  and  the  object  to  be 
melted,  any  desirable  degree  of  heat  may  be  obtained.  When  only  a  minute  portion  of 
metal  is  to  be  heated,  the  pointed  flame  is  used  with  a  mild  blast;  but  when  it  is  desir- 
able to  heat  a  large  surface  of  metal,  as  in  soldering  and  brazing,  a  much  larger  flame 
is  used.  This  is  produced  by  using  a  lamp  with  a  large  wick,  plentifully  supplied  with 
oil,  which  produces  a  large  flame.  The  blowpipe  used  has  a  larger  opening  than  the 
one  employed  for  the  pointed  flame,  and  is  held  at  a  little  distance  from  the  flame  and 
blown  vigorously,  so  as  to  spread  it  out  over  a  large  surface  of  the  work.  This  is  called 
the  bush  or  sheet  flame.  The  work  to  be  brazed  or  soldered  by  this  flame  is  generally 
supported  upon  charcoal. 

When  melting  metals  with  the  blowpijDe,  the  metal  to  be  melted  is  laid  upon  a  flat 
piece  of  charcoal,  which  has  previously  been  scooped  out  slighly  hollow  in  the  centre  to 
prevent  the  metal  from  running  off  when  melted.     If  it  is  desirable  to  run  the  metal  into 


Soldering — Blowpipes  and  Lamps. 


103 


a  mould  when  melted,  a  small  groove  or  lip  is  cut  in  (lie  charcoal,  and  when  Ihc  metal 
is  sufficiently  heated  it  is  poured  into  the  mould.  In  this  way,  jewellers  melt  most  of 
their  gold,  silver,  &c.,  when  making  rings  and  other  jewellery.  Tlio  cupel  is  also  used 
for  melting  metals  in  M'ith  the  blowpipe,  but  it  is  not  so  good  as  the  charcoal,  for  it  is 
liable  to  break  from  being  heated  unevenly,  and  spill  the  metals.  Several  different 
kinds  of  stationary  or  bench  blowpipes  are  used  by  jewellers,  braziers,  &-c. 

Two  examples  of  the 
152.  ^^^^-  mouth  blowpipe  are  shown 

in  Fig.  152,  the  form  a 
liaving  a  movable  nozzle 
which  may  be  screwed  on 
and  off,  thus  admitting  of 
the  use  of  a  jet  with  the 


]54. 


r3 


most  suitable  sized  orifice.     The  flange  h  is  convenient  for  holding  the  blowpipe  in  the 
mouth. 

Lamps  or  their  equivalents  show  a  variety  of  forms.      The   most    primitive  yet 
efficient  method  of  obtaining  a  flame  is  to  tie  a  bundle  of  dry  reeds,  coated  with  tallow 


156. 


by  immersion  in  melted  suet,  in  a  paper  wrapper,  and  siick  it  in  a  hole  iu  a  piece  of 
wood,  as  in  Fig.  153.  Sjnrit  lamps  differ  according  to  the  material  burned  in  them  and 
the  degree  of  heat  required  from  them.    A  handy  little  lamp  for  delicate  objects  is 


104 


Soldering — Blowpipes  and  Lamps. 


shown  in  Fig.  154.     One  made  by  Griffin  for  burning  a  mixture  of  wood  spirit  and  tur- 
pentine (4  volumes  to  1)  is  illustrated  in  Fig.  155.     Fletcher's  lamp  (Fig.  15G)  for  the 
same  mixture  has  the  spout  made  large  enough  to  accommodate  5  or  G  folds  of  1-in 
Boft  cotton  wick.   All  these  lamps  should  be  cajjped  when  not  iu  use 


Figs.  157  and  158 


159. 


represent  respectively  the  fixed  and  adjustable  forms  of  the  patent  self-acting  soldering 
lamps  with  blowpipes  attached.     Fig.  159  is  a  Bunsen  gas-burner. 

Blowers. — When  the  work  exceeds  the  capacity  of  the  mouth  blowpipe,  or  when  it 
is  too  continuous  to  be  done  with  the  mouth  alone,  a  mechanical  blower  must  be  used, 
and  the  selection  of  this  to  suit  the  work  required  is  a  matter 
of  considerable  importance.  The  temperature  of  a  given  flame, 
the  fuel  combustion  being  equal,  is  greater  in  inverse  proportion 
to  its  size.  The  smaller  a  flame  becomes  when  the  air  blast  is 
applied,  the  hotter  it  is,  and  the  more  work  it  will  do,  provided 
the  air  is  not  supplied  in  excessive  quantity.  Other  things 
being  equal,  a   high-pressure   blast  gives  the  most  poweiful 

153. 


flame,  and  the  pressure  of  the  air  supplied  is  therefore  a  matter  of  serious  importance. 
An  average  adult  can,  with  an  effort,  give  an  air  pressure  in  a  blowpipe  equal  to  about 
36  in.  of  water  pressure,  or  1^  lb.  on  the  sq.  in.  The  average  pressure  is,  however,  about 
half  this,  or  rather  less,  the  maximum  being  only  obtained  by  a  severe  strain,  which 
cannot  be  continued.  A  fan  worked  by  the  foot  will  give  an  air  pressure  equal  to 
about  i  to  1  in.  of  water.  A  fan  worked  by  jTOwer  will  give  air  at  1  to  5  in.  of  water 
pressure,  depending  on  its  speed  and  construction.  An  average  smiths'  bellows  about 
5  in.  pressure.  Small  heavily-weighted  circular  belloM's  about  8  to  10  in.  pressure. 
Eoot's  blower  driven  by  power,  24  in.  i>re3sure.     Fletcher's  foot  blower  No.  2,  15  in. 


Soldering— Blowpipes  and  Lamps.  105 

pressure.  Fletcher's  foot  blower  Nos.  3  and  5,  30  in.  iirossnro.  Fletcher's  foot  blower 
No.  4,  45  in.  pressure.     Cotton  and  Johnson's  foot  blower  (variable),  5  to  20  in.  pressure. 

The  temperature  of  a  blowpipe  flame  may  Ije  estimatod  from  tlio  above,  bcinj^  in 
close  i^roportion  to  the  pressure  of  air  supplied,  and  it  may  l)e  taken  ns  a  rou"h  rule  in 
brazing  or  hard  soldering  with  gas,  that,  given  an  air  pressure  equal  to  15  in.  of  water, 
a  blowpipe,  having  an  air  jet  of  -i-in.  bore,  will  braze  work  up  to  h  lb.  total  weight. 
One  with  an  air  jet  of  i-in.  bore  will  braze  up  to  about  2  11).  total  weight,  i.e.  2  brass 
weights,  each  1  lb.,  could  be  securely  brazed  together  with  a  blowpipe  with  J-in.  boro 
air  jet,  and  supplied  with  air  at  a  pressure  equal  to  15  in.  of  water,  or  10  oz.  on  tho 
sq.  in.  It  will,  of  course,  be  remembered  that  tho  areas  given  are  those  of  the  air  jet  or 
point  at  which  the  blast  leaves  the  blowpipe,  and  the  area  of  the  gas  supply  is  that  of 
the  space  between  the  air  tube  and  the  gas  tube  outside  it.  The  area  of  taps  and  pipes 
to  supply  these  must,  of  course,  be  larger,  to  prevent  friction  as  much  as  possible. 
When  anything  like  a  high  power  is  required,  it  is  of  the  first  necessity  that  any  elastic 
or  flexible  tube  used  shall  bo  perfectly  smooth  inside.  A  length  of  G  or  8  ft.  of  india- 
rubber  tube,  with  wire  inside,  will  reduce  a  gas  supply  or  a  pressure  of  blast  to  about 
one  half.  Practically  this  amounts  to  requiring  apparatus  double  the  size  for  the  same 
work,  and  it  therefore  does  not  pay  to  use  rough  tubing.  Applying  the  rule  to  other 
shapes  of  work,  it  may  be  taken  that  a  blowpipe  which  will  braze  a  block  of  2  lb.  total 
weight,  when  the  work  is  supported  on  a  good  non-conductor,  will  braze  brass  plate  up 
to  A  in.  or  -^^  in.  thick.  Its  capability  of  brazing  iron  is  not  so  great,  as  iron  does  not 
take  up  the  heat  of  the  blowpipe  so  readily  as  brass  does.  When  the  blowpipe  is 
eupplemeuted  by  either  a  bed  of  burning  coke  or  by  a  non-conducting  jacket  round  the 
work,  the  power  of  any  blowpipe  may  bo  extended  almost  without  limit,  as  little  of  the 
actual  work  of  heating  the  body  of  metal  is  done  by  the  direct  blowpipe  flame. 

In  the  construction  of  blowpipes  for  gas  they  should  be  so  proportioned  as  to  give  tho 
niaxinnnn  effect  for  the  minimum  of  fuel  and  blast.  To  do  this  the  air  pressure  available 
must  be  an  important  factor.  Speaking  roughly,  but  still  sufficiently  near  to  make  a 
correct  rule  to  work  by,  a  blowpipe  requires  1  of  gas  to  8  of  air.  If  the  gas  is  supplied 
at  a  pressure  eqnal  to  1  in.  of  water,  and  the  air  at  8  times  that  pressure,  the  area  of  the 
gas  and  air  pipes  should  be  equal,  to  get  the  best  efiect.  If  the  air  supply  is  equal  to 
16  in.  of  water  pressure,  the  gas  pipe  must  be  double  the  area  of  the  air,  and  so  on  in 
proportion.  Of  course  the  air  end  gas  supplies  can  be  adjusted  by  taps  easily,  but  in  the 
first  construction  of  a  blowpipe  for  large  work,  this  rule  must  be  adhered  to.  Any 
departure  from  it  reduces  the  power  of  tlie  blowpipe,  and  ignorance  of  this  simple  rule 
has  frequently  caused  failures  which  the  makers  of  blowpipes  have  been  unable  to 
explain. 

It  is  often  an  advantage  to  build  up  a  blowpipe  quickly  for  some  special  work,  and 
the  method  and  rules  for  construction  are  here  given,  bearing  in  mind  always  that  a  high- 
pressure  blast  gives  the  most  compact  and  highest  temperature  flame,  without  having 
any  actually  greater  quantity  of  heat  in  the  flame  produced. 

At  day,  pressure  =  10-lOths  on  the  gas  supply,  a  i-in.  jripe  with  a  J-in.  bore  tap  will 
Bupply  about  IJ  cub.  ft.  per  minute,  or  75  cub.  ft.  per  hour.  A  1-in.  bore  pipe  and  tap 
will  supply  about  5  cub.  ft.  per  minute.  About  25  cub.  ft.  of  gas  equals  1  lb.  of  coal  in 
fuel  value,  and,  therefore,  a  J-in.  gas  pipe  will  supply  at  the  rate  of  1  lb.  of  coal,  in  a 
gaseous  form,  in  20  minutes.  To  burn  this  in  a  blowpipe,  an  air  supply  of  10  cub.  ft. 
per  minute  is  required,  and  given  the  available  blast  pressure  the  area  of  tho  air  jet 
necessary  is  easily  found. 

For  the  construction  of  large  blowpipes  for  special  work,  the  stock  fittings  can 
generally  be  utilized,  and  an  efficient  blowpipe  built  up  in  a  few  minutes,  as  shown  in 
Fig.  160.  Nothing  more  is  necessary  than  3  short  bits  of  tube,  a  T  coupling  and 
diminishing  socket,  or  straight  union.  No  taps  are  necessary  on  tho  blowpipe,  if  not  at 
hand,  as  if  an  elastic  tube  is  used  the  flame  can  be  perfectly  controlled  by  squeezing  the 


106 


Soldering — Blowpipes  and  Lamps. 


tubes  between  the  fingers,  holding  them  in  the  same  way  as  the  reins  are  held  in  driving 
a  horse.  If  a  diminishing  socket  is  not  at  hand,  the  end  of  the  T-piece  can  be  plugged 
up  and  the  air  tube  fastened  into  this  plug,  and  it  will  be  a  convenience  if  an  elbow  is 
put  on  the  gas  inlet  close  to  the  T)  so  as  to  turn  the  gas  pipe  in  the  same  direction  as 
the  air  pipe.     In  this  form  it  makes  a  handy  and  convenient  blowpipe. 

For  any  except  very  small  work,  some  mechanical  blower  is  absolutely  necessary. 
Those  who  do  not  care  to  go  to  the  expense  of  any  of  the  apparatus  usually  sold,  can 
produce  a  good  make-shift  with  one  or  two  pairs  of  common  house  bellows.  If  an 
upholsterers'  or  sofa  spring  is  placed  between  the  handles  so  as  to  render  the  opening  of 
the  bellows  automatic,  the  pressure  of  the  foot  on  the  top  board  will  give  a  strong  blast 
of  air.  This,  although  intermittent,  acts  very  well  for  a  large  proi^ortion  of  work,  and  a 
full-sized  pair  of  house  bellows  will  supply  a  blowpipe  with  an  air  jet  of  full  -j  or  ^  in. 
bore.  A  continuous  blast,  at  all  events  for  soldering  and  brazing,  is  not  at  all  necessary, 
unless  the  maximum  possible  power  is  required.  To  obtain  a  continuous  blast  from  this 
arrangement  several  ways  may  be  adopted.  It  is  of  course  necessary  to  have  a  reservoir, 
which  is  always  under  pressure,  and  some  means  must  be  adopted  to  prevent  the  air  in  the 
reservoir  blowing  back  into  the  bellows,  whilst  they  are  being  lifted  between  the  strokes. 

If  a  square  tin  or  zinc  vessel  is  made,  with  a  sloping  partition,  shown  at  b  (Fig.  1Q1\ 

160. 


161. 


^as  JnleO 


the  partition  slightly  open  at  the  bottom,  and  the  vessel  half  filled  with  water,  the  air 
when  blown  by  the  bellows  through  the  pipe  c,  bubbles  up  through  the  water,  which 
makes  the  bottom  of  the  pipe  c  tight  against  the  return  of  the  air.  As  the  air  accumu- 
lates in  the  close  part,  it  presses  the  water  a  under  the  partition  to  the  other  side,  causing 
a  difference  in  level,  which  exerts  a  continued  pressure  on  the  air  pipe  on  the  top.  The 
deeper  this  vessel  the  heavier  the  air  pressure  which  can  be  obtained,  as  this  is  ruled  by 
the  difference  in  level  between  the  two  water  surfaces.  This  is  the  only  means  of  getting 
a  continuous  pressure  without  a  valve.  The  next  easiest  way  is  to  get  a  second  pair  of 
bellows,  plug  up  the  hole  underneath  the  inlet  valve  at  the  bottom,  and  in  this  plug 
insert  a  pipe  leading  from  the  first  pair  of  bellows.  The  second  pair  then  forms  the 
reservoir,  the  air  being  taken  from  the  nozzle  to  supply  the  blowpipe,  and  the  necessary 
pressure  must  be  obtained  by  weights  on  the  top  board  or  by  a  strong  spiral  spring  rest- 
ing on  the  top  board.  The  rule  with  house  bellows  is  that  they  are  made  in  a  wholesale 
rough  way,  and  very  few  are  anything  like  air-tight.  They  should  be  carefully  selected 
for  the  purpose  by  opening  fully,  stopping  the  nozzle  with  the  finger,  and  pressing  the 
handles  heavily  together.  Many  will  be  found  to  close  almost  as  quickly  with  the 
nozzle  stopped  as  with  it  open,  and,  of  course,  these  are  quite  useless  for  the  purpose. 


Soldering — Supports,  Tools. 


107 


Supports. — Work  to  be  brazed  needs  to  be  supported  on  a  bed  of  some  refractory 
material.  Often  a  fire-brick  or  piece  of  fire-luiup  is  used  for  heavy  work,  or  powdered 
pumice  or  charcoal  for  lighter  work.  A  fire-brick  forms  a  convenient  basis,  and  may  be 
hollowed  out  to  receive  a  dough-like  compound  of  1  part  fine  fire-clay  and  2  parts  charcoal 
dust  combined  by  adding  a  little  stiflf  rice-flour  paste,  as  Edwinson  suggests.  Or 
pumice  may  replace  the  fire-clay.  In  this  dough  the  article  is  embedded,  and  all  is  dried 
gently  before  the  brazing  begins.  Freeman  has  introduced  a  new  and  improved  heat 
deflector,  for  use  with  the  blowpipe,  as  a  support  for  tli  Work  whilst  it  is  being  brazed 
or  soldered.  This  article  is  made  of  a  very  light  porous  clay,  specially  prepared,  and  is 
corrugated,  so  as  to  allow  the  heat  to  pass  entirely  underneath  the  article  to  bo  soldered. 
It  is  superior  as  a  support  to  that  of  an  ordinary  fire-brick,  it  does  not  burn  like  com- 
position supports,  it  does  not  crackle  or  spit  like  charcoal,  nor  crumble  away  like  pumice. 
The  article  has  been  tested  by  many  of  the  leading  electroplate  and  jewellery  manu- 
facturers of  Birmingham,  who  speak  highly  in  their  testimonials  of  its  efficiency. 
Blocks  of  the  material  may  be  had  in  disc  form  14  in.  in  diameter,  or  in  lumps  12^  in. 
square  at»3s.  each. 


162. 


163. 


C: 


<^ 


165. 


16C. 


c 


Tools.— Some  of  the  tools  incidental  to  soldering  are  illustrated  above.    Fig.  162  is 
a  hornbeam  dresser  for  flattening  metal ;  Figs.  1G3,  1G4,  bossing  mallets ;  Figs.  165 


108 


SoLDEEiNG — Tools,  Heartli. 


166,  copper  bits;  Figs.  167  to  170,  soldering  ami  Lossing  irons;  Fig.  171,  a  ladle; 
Fig.  172,  a  shave-hook;  Fig.  173,  a  boxwood  chase  wedge;  Fig.  171,  a  boxwood 
turnpin. 


113. 


1G9. 


nt. 


i:o. 


i^^:^:^^:>^<^C&. 


171. 


1T2. 


Braziers'  Hearth. — lu  soldering  or  brazing  large  work  of  copper,  silver,  &c.,  an  open 
fire  is  used,  called  the  braziers'  hearth.  For  large  and  long  work,  this  hearth  is  made 
with  a  flate  iron  plate  about  4  ft.  by  3,  which  is  supjiorted  by  4  legs,  and  stands  on  the 
floor  at  a  suiHcient  distance  out  from  the  wall,  to  that  the  operator  can  get  all  around  it. 
In  the  centre  of  this  i>late  is  a  depression  about  6  in.  deep  and  2  ft.  long  by  1  wide,  for 
containing  the  fuel  and  fire.  The  fire  is  depressed  in  this  way  so  that  the  surface  of  the 
plate  may  serve  for  the  support  of  large  work,  such  as  long  tubes,  large  plates,  &c.  The 
rotary  fan  is  commonly  used  for  the  blast.  The  twyer  iron  is  similar  to  those  for  the 
common  blacksmiths'  forge,  but  with  a  larger  opening  for  admitting  the  blast  to  the  fire. 
The  nose  or  toi)  of  this  twyer  iron  is  fitted  loosely  into  grooves,  so  as  to  admit  of  easy 
renewal,  as  they  are  burned  out  in  a  very  short  time,  and  must  be  replaced  to  do  good 
work.  The  fire  is  sometimes  used  the  full  length  of  the  hearth,  in  which  case  a  long 
or  continuous  twyer  is  employed.  Occasionally  2  sf  parate  fires  are  made  on  the  same 
hearth.  In  this  case,  they  are  separated  by  a  loose  iron  plate.  The  hood  or  mouth  of 
the  stack  is  suspended  from  the  ceiling  over  the  hearth  with  counterpoise  weights,  so  that 
it  may  be  raised  or  lowered,  according  to  the  magnitude  of  the  work.  The  common 
blacksmiths'  forge  fire  is  frequently  used  for  brazing.  It  is  temporarily  converted  into 
a  braziers'  hearth  by  being  built  hollow  around  the  fire,  and  the  fire  removed  from  the 
wall  or  flue,  out  into  the  centre  of  the  hearth.  But  the  brazing  operation  injures  the 
fuel  so  that  it  cannot  be  again  used  for  ordinary  forging  of  iron  or  steel.  For  want 
of  either  the  braziers'  hearth  or  the  blacksmitlis'  forge,  the  ordinary  grate  made  be  used, 
or  it  is  better  to  employ  a  brazier  or  cliafing  dish  containing  charcoal,  aud  urge  the  fire 
with  a  hand-bellows,  which  should  be  blown  by  an  assistant,  so  that  the  operator  may 
have  both  hands  at  liberty  to  manage  the  work  and  fuel.  The  best  fuel  for  brazing  is 
charcoal,  but  coke  and  cinders  are  generally  used.  Fresli  coals  are  highly  injurious  to 
the  work,  on  account  of  tlie  sulphur  they  contain,  and  soft  or  bituminous  coal  cannot  be 
used  at  all  until  it  is  well  charred  or  converted  into  cinders.  Lead  is  equally  as  injurious 
in  the  fire  for  brazing  as  for  welding  iron  and  steel,  or  in  forging  gold,  silver,  or  copper,  for 
the  lead  is  oxidized  and  attaches  itself  to  the  metals  that  are  being  brazed  or  welded,  and 
prevents  the  union  of  the  metals,  and  in  all  cases  it  renders  tlie  metal  brittle  and 
unserviceable.     There  are  many  kinds  of  work  which  require  the  application  of  heat 


Soldering — Hearth ;  Hints. 


109 


175. 


having  the  intensity  of  the  forge  fire  or  the  furnace,  hut  in  a  nnniher  of  these  cases  it  ia 
only  desirable  to  heat  a  small  portion  of  tho  work,  and  avoid  soiling  the  surface  of  tlio 
remainder,  and  also  to  have  the  work  under  the  observation  and  guidance  of  the  operator 
as  in  brazing  or  soldering  small  articles  of  jewellery,  silver  plate,  &c.  In  these  cases, 
the  blowpipe  with  pointed  flame  is  generally  used,  and  in  many  cases  the  work  is  sup- 
IKjrted  upon  charcoal  so  as  to  concentrate  the  heat  upon  it. 

Heating  the  Iron.— Fig.  175  shows  a  simple  form  of  lamp  for  heating  tho  soldering- 
iron  :  a  is  the  casing ;  h,  lamp  and  uptake  ;  c,  flame ;  d,  bafllc-platu ;  e,  to»  of  etove  ; 
/,  tilt ;  g,  wires ;  h,  place  for  the  bit.  Make  tlie 
tilt  just  high  enough  for  the  proper  heating  of 
the  bit,  and  let  it  rise  1  in.  higher  at  tho  back. 
Adjust  the  lamp,  &c.,  that  tho  article  is  not  covered 
with  a  deposit  of  carbon  (soot). 

Tlie  following  is  a  simple  and  useful  adjunct 
to  the  "  solderer,"  in  order  to  do  away  with  the 
nuisance  caused  by  the  smoke  from  an  ojdinary 
gas-burner.  Take  a  piece  of  sheet  tin — say  7  in. 
by  7  in. ;  turn  it  round  into  a  cylinder,  and  rivet. 
(The  small  brass  nails,  to  be  had  at  any  iron- 
monger's, are  handy  ;  make  holes  with  a  bradawl 
and  snip  ofl'  the  tack  to  the  desired  length,  and 
rivet ;  4  will  be  plenty  in  cylinder.)  Vandyke  one 
end  all  round,  turn  down  a  flange  at  the  other 
end,  make  a  circular  cover  for  this  end,  and  fill 
full  of  holes  by  means  of  a  fine  sprig  bit ;  rivet 
this,  then,  on  to  flange  with  4  tacks ;  make  a  holo 
to  receive  an  ordinary  gas-burner — say,  2  in. 
from  the  bottom  or  vandyked  end,  and  solder  the 

burner  (the  new  brass  ones  are  the  handiest).  Now  procure  a  piece  of  vulcanized  rubber 
pipe  of  I  in.  bore,  draw  over  the  burner,  and  also  over  an  adjacent  burner  in  the  shop, 
and  turning  on  the  gas  you  have  a  beautiful  blue  and  smokeless  flame,  with  great  heat. 

Fletcher,  of  Warrington,  sells  veryuseful  little  implements  for  heating  the  soldering- 
iron  by  a  suitably  arranged  gas-jet. 

(Jj)  Hints. — (1)  The  soldering  of  2  metallic  surfaces  together  implies  something  moro 
than  mere  mechanical  union,  and  probably  depends  in  some  measure  ujwn  the  forma- 
tion of  au  alloy  between  the  solder  and  the  metals  joined  by  it :  hence  the  necessity  for 
clean  contact,  and  therefore  perfectly  bright  inoxidizod  surfaces.  To  ensure  this  condi- 
tion, various  solutions  are  used  just  at  the  moment  of  soldering.  The  most  common  is 
hydrochloric  acid  "  killed  "  with  zinc  (i.  e.  in  which  zinc  is  dissolved  until  the  acid  takes 
up  no  more),  forming  zinc  chloride,  which  runs  over  the  surface  exposed  to  it,  removing 
any  existing  oxide,  and  preventing  its  further  formation  by  the  action  of  the  air.  Sal- 
ammoniac  (ammonium  chloride)  sometimes  reijlaces  the  zinc  chloride,  or  is  used  in 
conjunction  with  it.  Powdered  rosin  applied  to  the  heated  metallic  surface  forms  a 
protective  vamish  which  excludes  the  air  and  prevents  oxidation.  With  the  same  object, 
borax  (sodium  biborate)  is  mingled  with  granulated  hard  solder  just  before  use,  either 
by  crushing  the  borax  and  mixing  dry,  or  by  dissolving  the  borax  in  water  and  making 
a  paste  of  the  solution  and  the  powdered  solder. 

(2)  "  Hard  "  or  "  strong  "  solder  is  commonly  known  as  "spelter,"  a  term  properly 
applied  to  commercial  zinc  ingots.  For  some  kinds  of  work,  commercial  si^eltcr  is  not 
so  well  suited  as  other  brasses ;  rbr  ordinarily  it  consists  of  equal  weights  of  zinc  and 
copper,  and  in  certain  cases  it  is  advisable  to  use  a  harder  solder  than  is  obtained  by 
these  proportions.  The  admixture  of  copper  and  zinc  produces  a  series  of  alloys 
differing  considerably  in  their  qualities,  and  when  tin  is  introduced,  tho  increase  or 


110  Soldering — Hints. 

decrease  of  the  zinc  and  tin  produces  a  compound  metal,  the  properties  of  which  are 
■widely  different  according  to  tharelative  quantities  of  the  ingredients  used  in  its  pro- 
duction. Spelter  when  home-made  is  best  prepared  by  melting  the  copper  and  zinc  in 
separate  crucibles,  the  copper  being  in  a  crucible  large  enough  to  hold  the  zinc  as  well. 
When  both  metals  are  thoroughly  melted,  the  zinc  is  poured  into  the  copper  crucible, 
the  two  being  stirred  well,  so  as  to  ensure  thorough  admixture,  when  the  alloy  is  poured 
out  on  to  a  bundle  of  birch  twigs  or  pieces  of  coarse  basket-work,  supported  over  a  tub 
of  water,  the  object  being  to  obtain  the  solder  in  the  form  of  fine  grains  with  an  irregular 
crystallization.  If,  when  taken  from  the  water,  the  spelter  is  not  sufficiently  uniform  in 
size  of  f^rain,  it  is  passed  through  a  sieve,  and  the  large  particles  are  crushed  in  a  cast- 
iron  mortar  or  any  suitable  appliance,  and  again  passed  through  the  sieve,  for  fineness 
and  uniformity  of  size  are  essential  to  the  accomplishment  of  some  examples  of  brazing 
in  a  thoroughly  satisfactory  manner.  Manufacturers  of  hard  solder,  however,  usually 
cast  it  into  ingots,  delaying  the  cooling  in  order  to  develop  as  much  as  possible  the 
crystallization,  which  is  found  to  facilitate  the  subsequent  crushing  and  sifting  of  the 
spelter.  The  term  "  brazing  "  is  often  applied  to  the  operation  of  "  hard  soldering,"  from 
the  fact  that  the  solder  used  is  really  a  brass. 

(3)  The  solder  found  in  commerce  generally  is  known  as  "  coarse,"  "  common,"  and 
"  fine " ;  and  tlie  respective  proportions  of  the  metals  are  supposed  to  be — for  coarse, 
2  parts  lead  to  1  of  tin ;  for  common,  equal  parts  ;  and,  for  fine,  2  parts  tin  to  1  of  lead. 
These  proportions  can  generally  be  detected  in  the  manufactured  article,  for  coarse 
solder  exhibits  on  its  surface  small  circular  spots,  caused  liy  a  partial  separation  of  the 
metals  on  cooling  ;  but  these  are  wanting  when  the  tin  exceeds  the  lead,  as  in  fine  solder. 
In  the  ordinary  solder  of  commerce,  it  is  very  rare  that  the  tin  exceeds  the  lead,  and 
No.  1,  or  hard  solder,  of  the  shops,  will,  as  a  rule,  be  found  to  vary  between  1|  and  2  of 
lead,  to  1  of  tin.  The  commoner  stuff— that  which  plumbers  use  for  making  wiped 
joints  in  leaden  pipes — contains  2|  to  3  parts  lead  and  1  of  tin. 

(4)  Solder  will  sometimes  get  contaminated  with  zinc,  burnt  tin,  lead,  iron,  &c., 
which  causes  it  to  "  work  short,"  "  set,"  or  crystallize,  contrary  to  the  general  rule. 
This  is  known  by  the  solder  quickly  curdling  or  setting  and  working  rough,  with  the 
tin  separating,  and  looking  like  so  much  sawdust,  except  in  colour,  which,  if  disturbed 
when  cooling,  is  a  kind  of  grey-black.  This  is  often  caused  by  overheating  the  metal, 
viz.  by  making  it  red  hot  or  by  dipping  brasswork  into  the  pot  for  tinning,  and  also 
when  soldering  brasswork  to  lead,  when,  if  brasswork  be  dipped  into  the  jiot  too  hot,  the 
zinc  leaves  the  copper  and  the  tin  takes  it  up,  because  tin  and  zinc  readily  mix.  A 
small  portion  of  zinc  will  also  cause  the  lead  and  tin  to  crystallize  or  separate.  If 
you  have  any  idea  that  there  is  zinc  in  your  solder  (the  least  trace  is  quite  sufficient), 
heat  it  to  about  800°  F.  (427°  C),  or  nearly  red  hot,  only  just  visible  in  the  dark  (if 
visible,  or  red  hot,  in  the  day  time,  it  will  be  at  least  1100°  F. :  red-hot  irons  do  not 
improve  solder).  Throw  in  a  lump  of  brimstone  (sulphur),  which  melts  at  226°  F. 
(108°  C),  but  at  a  greater  heat,  between  this  and  430°  F.  (221°  C)— just  below  the 
melting-point  of  plumbers'  solder,  it  tliickens,  and  from  480°  to  G00°  F.  (249°  to  315°  C.) 
remelts,  and  again  becomes  thinner.  At  773°  F.  (412°  C.)  the  zinc  melts,  and  being 
lighter  than  lead  or  tin,  has  a  chance  to  float,  especially  with  the  aid  of  sulphur.  The 
sp.  gr.  of  lead  is  11 '45;  tin,  7"3;  zinc,  6"8  to  7  (just  enough  to  rise);  and  sulphur, 
1  •  98.  The  last  named  readily  mixes  with  the  zinc,  &c.,  and  carries  the  lot  of  foreign 
matter  to  the  surface.  It  tdso  brings  up  all  the  oxidized  lead  and  tin  in  the  form  of  a 
whitish  powder  called  "  putty  powder,"  which  may  be  in  the  pot,  or  makes  it  fly  to  the 
iron.  Skim  the  solder  well,  and  after  the  heat  is  brought  down  to  about  400°  F 
(204°  C),  or  just  below  working-point,  stir  the  lot  well  up  in  plenty  of  tallow,  which 
will  free  the  sulphur,  and  your  solder  will  be  clean.  A  good  lump  of  rosin  will  improve 
it ;  and  add  a  little  tin.  If  you  have  very  much  zinc  present,  the  best  way  will  be  to 
granulate  the  solder  as  follows : — Just  at  setting  point,  turn  it  out  of  the  pot  and  break  it 


Soldering — Hints.  Ill 

np  with  the  dresser,  like  so  much  mould  or  sand.  Put  it  into  nn  earthcrnwaro  Lasin  or 
jar,  or  back  into  the  pot,  and  cover  it  with  hydrochloric  acid ;  kt  it  soak  for  a  day  or  so, 
then  well  wash  the  lot,  and  servo  it  as  above.  This  will  effectually  take  tlic  zinc  out. 
Afterwards  add  a  little  more  tin  to  compensate  for  that  destroyed  by  the  excessive  heat, 
and  the  acid.     A  little  arsenic  very  readily  carries  zinc  through  the  solder. 

Overheating  solder  renders  it  "  burnt,"  i.  e.  much  of  the  various  metals  present  is 
oxidized,  producing  a  cloggy  dull  mass;  this  is  remedied  by  the  process  just  described 
which  eliminates  the  injurious  oxides.  When  there  is  only  a  small  quantity  of  bad 
solder,  it  is  best  to  make  it  up  into  fine  solder,  or  uso  it  for  repairing  zinc  roofs.  Do 
not  put  bought  fine  solder  into  plumbers'  solder,  as  it  may  contain  all  sorts  of  metal. 
(P.  J.  Davies.) 

(5)  Soldering  zinc  and  galvanized  iron. — Zinc  may  be  soldered  as  readily  as  tin  by 
using  dilute  hydrochloric  acid  (i  its  bulk  of  rain-water  added)  as  a  flux  instead  of  rosin 
and  by  taking  care  to  keep  the  soldering-iron  well  heated. 

(G)  For  soldering  without  the  use  of  an  iron,  the  parts  to  be  joined  are  made  to  fit 
accurately,  either  by  filing  or  on  a  lathe.  The  surfaces  are  moistened  with  soldering 
fluid,  a  smooth  piece  of  tinfoil  is  laid  on,  and  the  pieces  are  pressed  together  and  tightly 
wired.  The  article  is  then  heated  over  the  fire  by  means  of  a  lamjj  until  the  thifoil 
melts.  In  this  way  2  pieces  of  brass  can  be  soldered  together  so  nicely  that  the  joint  can 
scarcely  be  found. 

(7)  For  soldering  brass  to  platinum,  put  a  piece  of  thick  brass  wire  in  a  handle,  and 
flatten  and  file  the  end  like  the  point  of  a  soldering  bit ;  dip  this  end  in  soldering  fluid, 
and,  holding  it  in  the  flame  of  gas  or  lamp,  run  a  little  solder  on  it ;  now,  having  put 
Bome  fluid  on  the  platinum,  which  will  require  to  be  supported  with  a  fine  pair  of  tongs, 
place  it  near  the  flame,  but  not  in  it,  at  the  same  time  heating  the  brass  wire  in  the  flamo 
with  the  other  hand,  and  as  soon  as  the  solder  melts  it  will  run  on  to  the  platinum  ;  you 
must  jjut  very  little  on,  and  take  care  the  solder  does  not  run  to  the  other  side.  Having 
applied  soldering  fluid  or  rosin  to  the  brass,  hold  the  two  together  in  any  convenient 
manner,  and  warm  them  in  the  flamo  till  the  solder  runs.  It  is  best  to  use  rosin  for 
electrical  work,  unless  the  work  can  be  separated  and  thoroughly  cleaned. 

(8)  Soldering  brass  wire. — For  making  a  chain,  procure  a  piece  of  hard  wood  or 
metal,  the  cross  section  of  which  will  be  the  same  shape  as  the  intended  links.  The 
wire  must  be  wound  on  this — then,  with  a  fine  saw,  cut  through  each  link  and  form  the 
chain  (or  a  part  thereof).  Have  a  large  piece  of  pumice  or  charcoal  (preferably  the 
latter),  with  a  nice  flat  surface,  and  arrange  the  chain  on  it  ready  for  soldering,  the  points 
of  each  link  being  turned  the  same  way  ;  the  solder  must  be  hammered  thin,  and  cut 
into  very  small  pieces.  Get  a  piece  of  borax,  and  grind  it  on  a  slate  with  water ;  now, 
with  a  small  camel-hair  pencil,  touch  each  joint  with  the  moist  borax,  and  with  the  point 
of  the  pencil  pick  up  a  piece  of  solder  and  place  it  over  the  joint.  When  every  link  has 
been  so  treated,  heat  them  with  the  blowpipe  till  the  solder  runs  ;  do  not  attempt  to  heat 
them  all  at  once,  but  direct  the  flame  (and  your  attention)  to  one  link  after  another,  till 
all  are  soldered  —then  boil  them  in  water,  to  which  is  added  a  little  sulphuric  acid.  For 
this  purpose  you  should  use  a  copper  or  porcelain  "  pickle  pan ";  for  solder,  take  a 
mixture  of  1  part  brass  and  2  of  silver,  melted  together  and  rolled  or  hammered  very  thin. 
In  order  to  make  neat  joints,  the  solder  must  be  cut  very  small,  and  only  put  the  boras 
just  where  you  wish  the  solder  to  run.  The  charcoal  or  pumice-block  you  can  grind  flat 
on  the  hearthstone,  or  use  an  old  file  for  the  purpose ;  an  ordinary  blowpipe,  which  you 
can  buy  for  M.,  will  answer  every  purpose.  You  can  also  buy  the  silver  solder  ready 
for  use.     Spelter  solder  can  be  used  for  this  purpose,  but  is  not  so  convenient. 

(9)  Soldering  brass  to  steel.— (a)  Clean  the  surface  of  the  steel,  and  with  a  fine  brush 
coat  the  steel  with  a  solution  of  copper  sulphate.  The  iron  reduces  the  copper  to  the 
metallic  condition,  in  which  condition  it  firmly  adheres  to  the  steel ;  then  solder  in  the 
usual  way.    (b)  Take  a  suitable-sized  piece  of  tinfoil,  and  wet  in  a  strong  solution  of 


112  SoLDEKiNG — Hints. 

commercial  sal-ammnniac ;  place  this  between  the  surfaces  to  be  soldered,  and  apply  a  liot 
iron  or  gas-flame.     The  surfaces  do  not  require  trimming:. 

(10)  Mending  cracked  bell. — The  crack  is  first  soldered  with  tin,  and  the  bell  is 
heated  to  dull  redness  or  nearly  so  for  a  little  time.  The  tin  has  the  property,  when 
heated  above  its  melting-point  to  nearly  redness,  of  rapidly  dissolving  copper,  an  alloy 
being  thereby  formed  in  the  crack  of  nearly  the  same  composition  as  the  bell  itself,  and 
which,  being  in  absolute  metallic  union  with  it,  is  quite  as  brittle  and  as  sonorous  as  the 
other  portions  of  the  bell. 

(11)  Soldering  iron  and  steel. — For  large  and  heavy  pieces  of  iron  and  tteel,  copper 
or  brass  is  used.  The  surfaces  to  be  united  are  first  filed  off,  in  order  that  they  may  bo 
clean.  Then  they  are  bound  together  with  steel,  and  upon  the  joint  a  thin  strip  of  sheet 
copper  or  brass  is  laid,  or,  if  necessary,  fastened  to  it  with  a  wire.  The  part  to  be  soldered 
is  covered  with  a  paste  of  clay,  free  from  sand,  to  the  thickness  of  1  in.,  the  coating  being 
applied  to  the  width  of  a  hand  on  each  side  of  the  piece.  It  is  then  laid  near  a  fire,  so 
that  the  clay  may  dry  slowly.  The  part  to  be  soldered  is  held  before  the  blast,  and 
heated  to  whiteness,  whereby  the  clay  vitrifies.  If  iron  is  soldered  to  iron,  the  piece 
must  be  cooled  off  in  water.  In  soldering  steel  to  steel,  however,  the  piece  is  allowed  to 
cool  slowly.  The  semi-vitrified  clay  is  then  knocked  off,  and  the  surface  is  cleaned  in  a 
proper  manner.  By  following  the  hints  given,  it  will  be  found  that  a  durable  and  clean 
soldering  is  obtained.  If  brass,  instead  of  copper,  is  used,  it  is  not  necessary  to  heat  so 
strongly ;  the  former  recommends  itself,  therefore,  for  steel.  Articles  of  iron  and  steel  of 
medium  size  are  best  united  with  hard  or  soft  brass  solder.  In  both  cases  the  seams  are 
cleanly  filed  and  spread  over  with  solder  and  borax,  when  the  soldering  seam  is  heated. 
Hard  brass  solder  is  prepared  by  melting  in  a  crucible  8  parts  brass,  and  adding  1  of 
previously  heated  zinc.  The  crucible  is  covered  and  exposed  to  a  glowing  heat  for  a  few 
minutes,  then  emptied  into  a  pail  with  cold  water,  the  water  being  strongly  agitated 
with  a  liroom.  Thus  the  metal  is  obtained  in  small  grains  or  granules.  Soft  brass  solder 
is  obtained  by  melting  together  6  parts  brass,  1  of  zinc  and  1  of  tin.  The  granulation  is 
carried  out  as  indicated  above.  Small  articles  are  best  soldered  with  hard  silver  solder  or 
soft  solder.  The  former  is  obtained  by  alloying  equal  parts  of  fine  silver  and  soft  brass.  In 
fusing,  the  mass  is  covered  with  borax,  and  when  cold,  the  metal  is  beaten  out  to  a  thin 
sheet,  of  which  a  sufficiently  large  and  previously  annealed  piece  is  placed  with  borax 
upon  the  seams  to  be  united  and  heated.  Soft  silver  solder  differs  from  hard  silver  solder 
only  in  that  the  former  contains  -^^^  of  tin,  which  is  added  to  it  during  fusion.  Yery  fine 
articles  of  iron  and  steel  are  soldered  with  gold,  viz.  either  with  pure  gold  or  hard  gold 
solder.  The  latter  can  be  obtained  by  fusion  of  1  part  gold,  2  of  silver,  and  3  of  copper. 
Fine  steel  wire  can  also  be  soldered  with  tin,  but  the  work  is  not  very  durable.  Hard 
and  soft  brass  solders  are  used  for  uniting  cojjper  and  brass  to  iron  and  steel,  silver  solder 
for  silver,  hard  gold  solder  for  gold. 

(12)  Soldering  silver. — The  best  solder  for  general  purposes,  to  be  employed  in 
soldering  silver,  consists  of  19  parts  (by  weight)  silver,  10  of  brass,  and  1  of  copper, 
carefully  melted  together,  and  well  incorporated.  ■  To  use  this  for  fine  work,  it  should  be 
reduced  to  powder  by  filing ;  the  borax  should  be  rubbed  up  on  a  slate  with  water,  to  the 
consistency  of  a  cream.  This  cream  should  then  be  applied  with  a  tine  brush  to  the 
surfaces  intended  to  be  joined,  between  which  the  powdered  solder  (or  wire)  is  placed,  and 
the  whole  is  supported  on  a  small  block  of  charcoal  to  concentrate  the  heat.  In  the 
hands  of  a  skilful  workman,  the  work  can  be  done  with  such  accuracy,  as  to  require  no 
scraping  or  filing,  it  being  only  needful  to  remove  the  borax  when  the  soldering  is  complete, 
by  immersion  in  "  pickle." 

Silver  soldering  as  applied  to  silversmiths'  work,  is  an  art  which  requires  great  caro 
and  practice  to  perform  it  neatly  and  properly.  The  solder  should  in  every  way  be  well 
suited  to  the  particular  metal  to  which  it  is  to  be  aj^plied,  and  should  possess  a  powerful 
chemical  affinity  to  it ;  if  this  is  not  the  case,  strong,  clean,  and  invisible  connections 


Soldering — Hints.  113 

cannot  be  effected,  and  that  is  partly  the  cause  of  roughness  in  goods,  and  not,  as  may 
more  frequently  be  supposed,  from  the  want  of  sldll  on  tlie  part  of  the  workman.  Tlie 
best  couuectioos  are  made  when  the  metal  and  solder  agree  as  nearly  as  possible  in 
uniformity  as  regards  fusibility,  hardness,  and  malleability.  Soldering  is  more  perfect 
and  more  tenacious  as  the  point  of  fusion  of  tlie  solder  rises.  Thus  tin,  which  greatly 
increases  the  fusibility  of  its  alloys,  should  not  bo  used  excepting  when  a  very  easy 
running  solder  is  wanted,  as  in  soldering  silver  which  has  been  alloyed  with  zinc.  Solders 
made  with  tin  are  not  so  malleable  and  tenacious  as  those  prepared  without  it.  Solders 
made  from  silver  and  copper  only  are,  as  a  rule,  too  infusible  to  be  applied  to  the  "cneral 
run  of  silver  goods.  Solders  are  manufactured  of  all  degrees  of  hardness,  the  hardest  beinw 
an  alloy  of  silver  and  copper ;  the  next  silver,  copper,  and  zinc ;  tho  most  fusible,  silver, 
copper,  and  tin,  or  silver,  brass,  and  tin.  Arsenic  is  sometimes  used  to  promote  fusion 
but  its  poisonous  vapours  render  its  use  inadmissible.  In  applying  solder,  of  whatever 
composition,  it  is  of  the  utmost  importance  that  the  edges,  or  parts  to  be  united,  should  bo 
chemically  clean  ;  and  for  the  purpose  of  protecting  these  parts  from  the  action  of  tho  air 
and  oxidation  during  the  soldering  process  they  are  covered  with  a  flux,  always  borax 
which  not  only  effects  the  objects  just  pointed  out,  but  greatly  facilitates  the  flow  of  tho 
solder  to  the  required  places.  Silver  may  be  soldered  with  silver  of  a  lower  quality,  but 
easy  running  solder  may  be  made  of  13  dwt.  fine  silver,  G  dwt.  brass;  the  composition 
of  brass  being  so  uncertain,  it  is  best  to  fuse  zinc  and  copper  with  the  silver,  and  the 
following  proportions  make  a  very  easy  running  solder :  12  dwt.  fine  silver,  6  dwt.  pure 
copper,  1  dwt.  zinc.  Brass  sometimes  contains  lead,  which  burns  away  in  soldering  and 
must  be  carefully  guarded  against.  Solder  for  filigree- work  is  prepared  by  reducing 
easy  flowing  solder  filings  and  mixing  it  with  burnt  boras  powdered  fine.  In  this  state  it 
is  sprinkled  over  the  work  to  be  soldered,  or  the  jxarts  to  be  soldered  are  painted  with 
wet  borax,  and  the  solder  filings  are  sifted  on  and  adhere  to  the  borax.  The  flux  which 
adheres  to  the  work  after  soldering  is  removed  by  boiling  the  article  in  a  pickle  of  sul- 
phuric acid  and  water,  1  part  to  30. 

(13)  Soldering  glass  to  metal. — This  may  be  effected  by  first  coating  the  glass  with 
lead,  as  is  sometimes  done  to  give  a  bright  reflecting  surface.  Small  flat  pieces  of  glass 
are  painted  over  on  one  side  with  chalk  or  colcothar  and  water,  and  then  left  to  dry. 
They  are  placed  with  the  coated  side  downwards  on  the  bottom  of  a  flat  cast-iron  tray 
about  1  ft.  square,  surrounded  by  a  vertical  border  of  1  to  IJ  in.,  and  are  gradually  heated 
in  a  large  muffle  to  a  temperature  somewhat  above  the  melting-point  of  lead.  The  tray 
is  withdrawn,  and  melted  lead  is  immediately  poured  into  it  sufficient  to  cover  the  glass, 
wliich  is  held  down  by  pieces  of  wire.  A  slightly  oscillating  movement  is  given  to  the 
tray,  so  as  to  cause  the  molten  lead  to  flow  gently  backwards  and  forwards.  After  a  short 
time,  a  plug  is  taken  out  of  the  corner  of  the  tray,  which  is  tilted  to  let  the  lead  run  off  as 
completely  as  possible.  The  pieces  of  glass  will  now  be  covered  with  a  firmly-adherent 
film  of  lead.  The  lead  employed  should  be  of  good  quality  ;  and  in  order  to  prevent  it 
from  becoming  mixed  with  any  oxide  which  may  have  formed  on  its  surface,  the  tray  is 
provided  with  a  gutter-like  arrangement,  leaving  only  a  slit  for  the  passage  of  the  lead. 
The  tray  is  suspended  at  one  end  by  a  chain,  and  held  by  tongs  at  tho  other.  Glass 
buttons  thus  backed  with  a  lead  coating  have  their  shanks  soldered  on  (Dr.  Percy).  Solder 
may  also  be  made  to  adhere  to  glass  by  first  coating  the  glass  surface  with  amalgam. 

(14)  Soldering  platinum  and  gold.— To  make  platinum  adhere  firmly  to  gold  by 
soldering,  it  is  necessary  that  a  small  quantity  of  fine  or  IS-carat  gold  shall  bo  sweated 
into  the  surface  of  the  platinum  at  nearly  a  white  heat,  so  that  the  gold  shall  soak  into 
the  face  of  the  platinum  ;  ordinary  solder  will  then  adhere  firmly  to  the  face  obtained  in 
this  manner.  Hard  solder  acts  by  partially  fusing  and  combining  with  the  surfaces  to  be 
joined,  and  platinum  alone  will  not  fuse  or  combine  with  any  solder  at  a  temperature 
anything  like  the  fusing  point  of  ordinary  gold  solder. 

(15)  Mending  tin  saucepan.— The  article  is  first  scoured  out  with  strong  soda  water, 

z 


114  Soldering — Hints. 

and  the  hole  is  scraped  quite  clean.  If  smnll  enough,  it  is  covered  v?ith  a  drop  of  solder, 
applied  after  the  spot  has  been  moistened  with  "killed  spirits."  If  this  plan  will  not  suffice, 
a  larger  space  must  be  cleansed  and  a  small  patch  of  tin  laid  on.  Wlien  the  bottom  is 
seriously  impaired,  the  quickest  and  best  method  is  to  cut  it  off  and  replace  it  by  a  new  one. 

(16)  Soldering  brass. — All  kinds  of  brass  may  be  soldered  with  Bath  metal  solder 
(70  copper,  21  zinc)  or  soft  spelter,  using  borax  as  a  flux.  A  good  pilan  is  to  spread  on  a 
little  paste  of  borax  and  water  and  lay  a  bit  of  tinfoil  on  this,  then  heating  till  the  tin 
melts  and  runs,  and  thus  coats  the  surface.  Work  previously  tinned  in  this  way,  can  be 
joined  neatly  and  easily. 

(17)  Soldering  pewters  and  compo  pipes. — These  require  powdered  rosin  as  a  flux, 
■with  very  thin  strips  of  the  more  fusible  solders,  care  being  taken  that  the  soldering- 
iron  is  not  too  hot. 

(IS)  Laying  sheet  lead. — In  laying  sheet  lead  for  a  flat  roof,  tlie  joints  between  the 
sheets  are  made  either  by  "  rolls,"  "  overlaps,"  or  soldering.  la  joining  by  rolls,  a  long 
strip  of  wood  2  in.  square,  flat  at  the  base  and  rounding  above,  is  placed  at  each  seam ; 
the  edge  of  one  sheet  is  folded  round  the  rod  and  beaten  down  close,  and  then  the 
corresponding  edge  of  the  next  sheet  is  folded  over  the  other.  In  overlapping,  the 
adjacent  edges  of  the  2  sheets  are  turned  up  side  by  side,  folded  over  each  other,  and 
closely  beaten  down.     Soldering  is  not  adopted  when  the  other  plans  can  be  carried  out. 

(19)  Mending  leaden  pipe. — When  a  water  pipe  is  burst  by  frost,  thcdamaged  portion 
must  be  cut  out  and  replaced  by  a  length  of  new  pipe,  in  the  following  manner.  The 
ends  to  be  joined  are  sawn  off"  square,  then  the  open  end  of  the  lower  section  is  enlarged 
by  inserting  a  boxwood  turnpin  and  driving  it  down  by  light  blows  till  the  opening  is 
large  enough  to  admit  the  lower  end  of  the  new  length,  which  is  rasped  thinner  all 
round  to  facilitate  this  operation.  The  top  end  of  the  new  length  and  the  open  end  of 
the  upper  section  are  then  served  the  same  way.  The  surfaces  to  be  joined  are  scraped 
qnite  bright,  either  by  a  shave-hook  or  by  a  pocket-knife,  and  then  fitted  together,  thus 
forming  a  couple  of  circular  ditches,  as  it  were.  Into  these  is  sprinkled  a  little  powdered 
rosin  to  keep  the  surfaces  bright,  and  then  molten  solder  is  poured  in  from  a  ladle  till  the 
ditches  are  quite  full.  Adhesion  between  the  solder  and  the  pipes  is  then  brought  about 
by  passing  the  point  of  a  hot  soldering-iron  round  the  ditches,  the  heat  of  the  iron  being 
sufficient  to  liquefy  the  solder  and  just  fuse  the  surface  of  the  lead,  but  it  must  not  be  so 
hot  as  to  melt  the  lead. 

(20)  Gas  for  blowpipe  work. — Fletcher,  of  Warrington,  the  well-known  inventor 
of  so  many  improved  appliances  for  the  employment  of  gas  in  the  workshoi),  has 
published  some  interesting  remarks  on  the  use  of  the  blowpipe.  Where  available,  there 
is  no  fuel  to  equal  gas  for  general  blowpipe  work,  and  in  using  the  blowpipe  with  gas,  it 
is  usual  to  cut  a  notch  or  groove  in  the  upper  side  of  the  open  end  of  a  |-iu.  brass  tube,  so 
as  to  allow  the  top  of  the  blowpipe  to  rest  in  it,  pointing  in  the  same  direction  as  the 
opening  iu  the  gas  pipe.  The  blowpipe  tip  should  then  be  placed  in  the  notch,  and  a 
wire  bound  round  both  in  such  a  manner  that  the  blowpipe  is  held  firmly  in  position, 
and  still  can  be  easily  drawn  out  backwards.  This  arrangement  forms  a  carrier  for  the 
blowpipe,  which  leaves  the  hands  at  liberty,  and  enables  the  whole  attention  to  be 
directed  to  the  work.  A  short  length  of  tube  made  like  this  could  be  carried  in  the 
tool-bag,  and  connected  to  any  available  gas  supply. 

For  hard  soldering,  where  the  solder  used  melts  at  a  heat  approaching  redness,  and 
sometimes  at  a  still  higher  temperature,  the  same  form  of  blowpipe  and  the  same  source 
of  heat  are  commonly  used,  except  that  as  the  work  is  usually  done  in  fixed  workshops, 
the  sources  of  heat  do  not  require  to  be  portable,  and  are  therefore  usually  confined  to 
gas,  or,  where  this  is  not  available,  to  a  lamp,  having  fixed  on  the  upper  side  of  the  wick 
tube,  m  a  convenient  position,  a  support  of  wire,  or  other  material,  to  carry  the  front  of 
the  blowpipe.  Sometimes  the  blowpipe  is  made  as  a  simple  straight  tube,  sliding  in  a 
ioose  "ollar,  the  blowpipe  in  this  case  being  about  3  or  4  in.  long.    At  the  opi30iite  end 


Soldering — Hints.  115 

of  the  jet  is  fixed  about  14  or  IG  in.  of  small  indiarubbcr  tubing  (feeding-bottle  tube), 
■which  is  used  for  blowing.  The  sliding  motion  of  tlie  blowpipe  is  necessary,  bo  that  the 
jet  can  either  be  drawn  back,  giving  a  large  rougli  flare  for  general  beating,  or  it  can  be 
pushed  into  the  flame,  so  as  to  take  up  part  only  and  give  a  finely  pointed  jet  on  any  part 
where  the  solder  requires  to  be  fused.  When  gas  is  used,  the  sliding  motion  of  the  blow- 
pipe is  not  necessary,  as  the  flame  can  be  altered  equally  well  by  the  gas  tap,  and  it  is 
therefore  usual  to  make  gas  blowpipes  with  fixed  jets. 

Another  form  has  the  blowpipe  coiled  as  a  spiral  round  the  gas  tube,  both  gas  and 
air  being  heated  before  burning  by  a  Bunsen  burner  underneath.  This  gives  a  very 
much  greater  power  for  small  work,  but  possesses  no  advantage  whatever  for  large 
flumes.  On  the  contrary,  when  the  maximum  bulk  of  work  is  to  be  heated  with  a  mouth 
blowpipe,  a  better  result  is  obtained  with  a  cold  blast  of  air,  and  the  advantage  of  the 
hot  blast  is  only  perceived  when  a  small  pointed  flame  is  used.  When  this  blowpipe  is 
used  for  soldering,  the  bullc  of  the  work  should  be  heated  up  first  with  the  cold  blast, 
and  the  lower  Bunsen  turned  on  a  fesv  seconds  before  the  small  pointed  flame  is  required 
for  finishing  the  soldering.  The  hot  blast  has  one  advantage  peculiar  to  itself  in  addition 
to  the  high  temperature  of  the  small  flame ;  it  requires  no  chamber  for  condensed  mois- 
ture. The  moisture  of  the  breath,  instead  of  appearing  as  occasional  splashes  of  wet  on  the 
work,  at  critical  times,  is  converted  into  steam,  and  goes  to  assist  the  blast  from  the  lungs. 

(21)  Blowpipe  brazing. — For  brazing,  where  powdered  or  grain  spelter  (a  very 
fusible  brass)  is  used,  the  borax  is  mixed  as  a  powder  with  a  spelter,  usually  with  a  little 
water,  but  sometimes  the  work  to  be  brazed  is  made  hot  and  dipped  into  the  dry  powder 
mixture,  which  partially  fuses  and  adheres.  In  either  case,  care  is  requisite  not  to  burn 
or  oxidize  the  grains  of  the  sjDolter  with  the  blowpipe  flame,  or  it  will  not  run  or  adhere 
to  the  surface  to  be  brazed  ;  and  for  such  small  work  as  can  be  done  with  the  mouth 
blowpipe,  it  is  better  to  discard  spelter  entirely,  and  use  eitlier  common  silver  snider  (an 
alloy  of  1  silver  and  2  tinned-brass  pins),  or  what  is  still  better  an  alloy  of  13  parts 
copper  and  11  fine  silver.  If  fine  silver  is  not  easily  to  be  got,  the  same  alloy  can  be  made 
by  equal  weights  of  copper  and  coin  silver.  The  solder  should  be  rolled  into  thin  sheets, 
cut  into  small  bits  of  the  shapes  and  sizes  required,  and  put  into  a  small  saucer,  contain- 
ing a  rather  thin  pasty  mixture  of  powdered  borax  and  water.  The  surfaces  of  the  joint 
to  be  soldered  should  be  brushed  with  this  mixture,  using  a  small  camel-hair  brush,  the 
bit  of  solder  being  put  in  its  position  either  with  the  brush  or  a  fine  pair  of  tweezers. 
The  heat  of  the  blowpipe  must  then  be  ajDplied  very  slowly.  The  borax  dries  up  and 
swells  enormously,  frequently  lifting  the  solder  along  with  it.  The  borax  then  sinks 
down  again  and  begins  to  fuse.  There  is  now  no  risk  of  blowing  the  solder  away,  and  the 
full  blast  can  be  at  once  applied,  directing  the  flame  principally  round  the  solder  so  as  to 
heat  the  body  of  the  work.  When  hot  enough,  the  solder  begins  to  fuse  and  adhere  to 
the  work,  and  the  flame  must  now  be  instantly  reduced  to  a  small  point,  and  directed  on 
the  solder  only,  which  usually  fuses  suddenly.  The  instant  the  solder  runs,  the  blast 
must  be  stopped  by  the  tip  of  the  tongue,  or  in  delicate  work  mischief  may  be  done  which 
may  take  hours  to  make  good. 

One  great  difficulty  with  beginners  is  in  soldering  two  or  more  parts  in  exact  positions 
relatively  to  each  other,  these  parts  being  of  such  a  form  tliat  they  cannot  be  held  in 
position.  The  way  to  overcome  the  difficulty  is  this :  With  a  stick  of  beeswax,  the  end 
of  which  has  been  melted  in  a  small  flame,  stick  the  parts  together  as  required.  The 
was  is  sufficiently  soft  when  cold  to  admit  of  the  most  exact  adjustment  of  parts,  and  it 
must  surround  the  parts  only  which  are  to  be  soldered.  Make  a  mixture  of  about  equal 
parts  of  plaster-of-paris  and  clean  sand,  and  stir  this  uj)  in  a  cup  or  basin  with  sulticient 
water  to  make  a  paste,  turn  it  out  on  to  a  sheet  of  paper,  and  bed  the  work  to  be  soldered 
into  it,  taking  care  that  the  part  covered  with  was  shall  be  freely  exposed.  When  this 
is  set  hard,  say  in  about  10  minutes,  slowly  warm  it  over  a  Bunsen  flame,  or  near  a  fii'C 
(if  suddenly  heated  it  will  break  up) ;  wipe  the  aielted  was  oflf  with  a  small  ball  cf  wool ; 

i2 


116  Soldering — Hints. 

apply  the  borax  aud  solder  as  before  mentioned,  and  continue  the  slow  beating  up  until 
the  wliole  mass  is  hot  enough  to  comjilete  the  soldering  with  the  blowpipe.  If  a  light 
bit  has  only  to  be  carried  or  held  in  position  after  fixing  with  wax,  as  before  mentioned, 
a  bridge  or  arm  may  be  made  between  the  pieces  with  a  verj'^  stiti'  paste  made  of  common 
whiting  and  water,  or  a  mixture  of  clay,  whiting,  and  water.  Tliis,  being  only  small  iu 
bulk,  dries  much  more  quickly  than  the  plaster  and  sand,  but  it  requires  also  very  slow 
heating  at  first,  so  as  to  drive  the  moisture  out  gradually,  otherwise  it  explodes  as  steam 
is  formed  inside,  and  the  whole  work  has  to  be  recommenced.  The  Indian  jewellers  in 
making  filagree  work  use  clay  alone  for  holding  the  parts  together,  but  it  is  very  slow 
in  drying,  and  requires  much  more  care  in  use  tlian  either  of  the  forms  given. 

When  soldering,  the  work  has  to  be  supported  in  such  a  manner  that  it  can  be  turned 
about  and  its  positions  altered  quickly,  more  especially  when  a  fixed  blowpipe  is  used, 
and  for  this  pmpose  it  is  common  to  use  either  a  lump  of  pumice  or  a  small  sheet-iron 
pau  with  a  handle,  and  filled  with  broken  pumice,  broken  charcoal,  and  plaster-of-jmris, 
or  other  non-conductor.  The  best  material  is  willow  charcoal,  and  the  best  result  can 
be  obtained  by  its  use,  as,  burning  with  the  heat  of  the  blowpipe,  it  gives  oif  heat  aud 
assists  the  workman,  giving  a  greater  power  than  when  any  other  support  is  used.  Oak 
charcoal  is  not  admissible,  as  it  crackles  and  disturbs  the  work.  For  a  permanent 
support,  which  does  not  burn  away  to  any  practical  extent,  the  best  is  a  mixtui'o  of 
finely-iMwdered  willow  charcoal  and  a  little  china  clay,  made  into  a  stiff  paste  with  a 
rice-flour  starch,  and  rammed  into  a  mould.  These  are  to  be  bought  in  manj-  shapes, 
and  are  the  most  convenient  for  all  jiurposes. 

Speaking  generally  of  the  mouth  blowpipe,  the  most  practised  users,  as  a  maximum 
feat,  might,  with  gas,  soft  solder  a  3-in.  lead  pipe,  or,  with  a  lamp,  do  the  same  with  a 
IJ-in.  pipe.  In  hard  soldering  (with  silver  solder  or  spelter),  it  is  usually  as  much  as 
can  be  done  to  solder  properly  any  work  weighing  over  3  oz.,  if  gas  is  used ;  or  about 
half  this  weight  with  a  lamp;  although  in  exceptional  cases,  using  a  charcoal  support, 
these  weights  may  be  exceeded,  and  more  especially  if  the  bulk  of  the  work  is  heated 
up  by  a  fire  or  other  means  so  as  to  admit  of  an  extra  strain  being  put  on  the  lungs  for 
a  short  time  for  finishing  only.  It  is  a  common  practice  for  heavy  or  awkwardly-shaped 
work — where  the  heat  is  liable  to  be  conducted  away  quickly — to  support  the  work  on  a 
bed  of  burning  coke  or  charcoal,  using  the  blowpipe  only  for  running  the  solder  whilst 
tlie  body  of  metal  is  heated  by  the  burning  coke.  By  this  assistance  the  capacity  of 
any  blowpipe  is  doubled,  or  more  tlian  doubled,  and  when  the  work  to  be  done  is  beyond 
the  capacity  of  tlie  blowpipes  available,  this  remedy  is  a  valuable  one. 

SHEET-METAL  WORKING.— By  the  term  "  sheet  metals  "  is  meant  those 
jnetals  and  alloys  which  are  used  in  thin  plates  or  sheets,  such  as  brass,  coj^per,  lead,  tin, 
zinc,  tinned  iron  (tin  plate),  and  thin  sheet  iron.  The  arts  of  making  gold,  platinum, 
and  tin  foils,  and  platinum  vessels  for  chemical  operations,  are  obviously  embraced  iu 
the  term,  but  these  trades  are  too  special  to  warrant  description  here. 

The  combined  strength,  durability,  lightness,  and  clean  smooth  surface  of  sheet 
metal,  render  it  particularly  useful  in  a  vast  number  of  articles  where  these  qualities 
are  desirable.  Another  most  important  property  possessed  by  the  majority,  especially 
copper  aud  tin,  is  that  of  assuming  various  shapes  without  fracture  by  simple  hammering. 

Striking  out  the  Patterns. — As  the  metal  is  procurable  only  in  flat  sheets  of 
various  dimensions  and  thicknesses,  some  knowledge  of  geometry  is  required  to  deter- 
mine how  the  flat  piece  is  to  be  marked  and  cut  in  order  to  produce  the  shape  decided 
on  for  the  finished  article. 

There  is  scarcely  any  end  to  the  variety  and  intricacy  of  pattern  which  may  bo 
introduced  into  sheet-metal  goods ;  but  when  the  surface  is  very  irregular  it  becomes 
necessary  to  employ  machines  for  stamping  out  the  design,  or  rolls  for  impressing  it  on 
the  metal.  Apparatus  designed  fur  these  purposes  will  be  described  further  on ;  but 
many  simple  articles  can  be  constructed  without  such  aid.    In  measuring  the  metal  in 


Sheet-Metal  Working. 


117 


sheet  to  make  an  article  of  any  desiied  dimensions,  allowanco  imist  bo  made  for  the 
auiount  of  metal  used  up  in  forming  the  joint,  when  tliat  is  to  bo  of  the  lapped  kind. 
Whore  the  edges  only  abut  against  eacli  otlier,  no  such  allowanco  is  needed.  It  is 
generally  between  }  and  i  in.  per  joint,  according  to  the  thickness  of  the  metal  used  and 
tlie  strength  required  in  the  joint.  Before  cutting  out  tlie  piece  of  sheet  metal  cor- 
responding to  the  dimensions  aimed  at,  it  is  well  to  make  a  pattern  in  stout  browa 
jiapcr,  and  fold  it  up  so  as  to  make  a  counterpart  of  the  article  in  view.  Unlbresceu 
errors  can  then  easily  bo  rectified,  and  tlie  metal  cut  exactly  to  the  corrected  pattern, 
without  risk  of  waste.  The  following  diagrams  and  examples  illustrate  the  manner  of 
striking  out  tlie  metal  for  many  objects  of  general  application. 

Relations  of  Circles. — The  diameter  of  a  circle  is  0"31831  times  the  circumference  ; 
the  circumference  is  3'HIG  times  the  diameter;  the  area  (external  surface)  is  the 
diameter  multiplied  by  itself  (squared)  and  by  0" 785-4;  the  diameter  multiplied  by 
0-SSG2  equals  the  side  of  a  square  of  the  same  area  ;  the  side  of  a  square  multiplied  by 
1'12S  equals  the  diameter  of  a  circle  of  the  same  area;  the  diameter  multiplied  by  tho 
circumference  equals  the  surface  of  a  globe. 

Cones. — The  solidity  of  a  cone  equals  i  the  product  of  the  area  of  the  base  multiplied 
by  the  perpendicular  height ; 
tho  convex  surface  equals  half 
the  product  of  the  circum- 
ference of  the  base  (diameter 
X  3-141G)  multiplied  by  the 
slant  height ;  the  slant  surface 
of  a  truncated  (the  top  cut  off) 
cone  equals  half  the  product  of 
the  sum  of  the  circumferences 
of  the  2  ends  multiplied  by  the 
slant  height. 

To  strike  out  a  sheet  to 
cover  a  whole  cone,  describe  an 
arc  equal  in  length  to  the 
desired  circumference,  and  at 

17.3. 


the  radius  cf  the  required  height.  In  Fig.  170,  a  is  the  desired  cone,  having  a  circum- 
ference at  the  base  e  of  15  in.,  and  a  height  d  e  oiB  in. ;  then  the  length  between  b  c 
must  be  15  in.,  and  the  length  between  (Z  e  8  in. 


118 


Sheet-Metal  Working. 


When  only  a  frustrum  of  a  cone  is  required,  as  for  instance  a  funnel  fitted  over  a  pipe 
end,  or  the  shoulder  top  of  a  can,  the  same  law  holds  good  ;  but  in  this  case  a  second 
arc  must  be  described  equal  in  length  to  the  smaller  circumference.  Thus,  in  Fig.  177, 
supposing  the  ring  a  to  have  a  larger  circumference  of  12  in.  at  the  base,  and  a  smaller 
circumference  of  10  in.  at  the  top,  -with  a  height  of  7  in. ;  then  2  arcs  have  to  be 
desfl'ibed  at  radii  7  in.  apart,  from  the  centre  h  (whicli  is  the  point  where  the  sides  of  a 
would  cut  each  other  if  prolonged),  the  larger  arc  c  measuring  12  in.  long,  and  the 
smaller  d  10  in.  Fig.  178  is  another  example  where  the  shoulder  has  a  much  shallower 
slope,  and  when  consequently  the  inner  arc  d  is  much  smaller  than  the  outer  c. 

Cylindrical  Tubes. — The  width  of  sheet  required  to  form  a  cylinder  is  ascertained  by 
multiplying  the  desired  diameter  of  the  cylinder  by  3  ■1416  ;  the  diameter  of  a  cylinder 
made  from  asheetof  known  width  will  be  the  product  of  that  width  multiplied  by  0*  31831. 

Among  the  most  frequent  operations  in  sheet-metal  working  is  the  adjustment  of 
cylindrical  pipes  to  each  other  at  various  angles,  and  in  various  positions. 

If  it  be  desired  to  join  2  pipes  of  equal  diameter  nt  right  angles  to  each  other, 
proceed  as  in  Figs.  179,  180.     The  T-pi<^ce  a  will  fit  the  outline  of  the  main  pipe  6,  as 

180. 


€U 


a> 


^ 


Cb 


shown.  To  strike  out  this  f-piece,  take  a  sheet  having  the  same  width  as  the  distance 
between  c  d,  and  the  same  length  as  tlie  circumference  of  the  T-piece.  Divide  the 
circumference  into  halves  by  the  line  e  ;  then  draw  tlie  line/  at  the  level  of  the  contact 
line  of  the  main  pipe  b ;  finally  describe  2  curves  g  commencing  at  the  point  h  on  tlio 
line  e,  touching  the  line  /,  and  terminating  at  the  points  c.  These  curves  g  must  be 
sketched  in,  as  they  do  not  form  correct  arcs  of  a  circle,  but  are  somewhat  deeper.  The 
seam  joining  the  edges  c  d  will  be  on  one  of  the  long  sides  of  the  T-piece.  The  exact 
delineation  of  the  curve  g  may  be  attained  by  dividing  the  half-eircumference  into  a 
number  of  equidistant  spaces  by  vertical  lines,  which  are  numbered  or  lettered  ; 
equivalent  lines  then  drawn  at  the  same  distances  and  of  the  same  lengths  on  the  sheet^ 
indicate  the  sweep  of  the  curve. 

Tools. — For  small  operations,  the  tools  required  may  be  said  to  consist  simply  of 
a  mallet,  shears,  and  a  few  shapes  for  moulding  on ;  but  many  useful  little  machines 

181. 


have  been  introduced  into  the  trar'ie,  and  elTect  considerable  saving  in  labour.  The 
ordinary  boxwood  tinmen's  mallet  should  have  the  paul  rounding  at  one  end  and  flat  at 
the  other.     Tinmen's  pliers  are  shown  in  Fig.  181. 


Sheet-Metal  Working. 


119 


Cutting  Tools, — Shears  are  made  in  several  patterns,  according  to  tlie  stoutness  and 


tonglmess  of  the  material  to  be 
platers'  hand  shears ;  Figs.  183, 
and  both  are  intended  for  use 
in  a  fixed  position  on  a  bench. 
Fig.  185  is  a  guillotine  shears. 
Fig.  186  is  a  machine  for  cutting 
edges  true.  Fig.  187  is  a 
machine  for  cutting  out  circles. 
Fig.  188  is  a  pair  of  follies  for 
punching  holes.  Fig.  189  repre- 
sents a  contrivance  for  cuttin2: 


cut.     Fig.  182   rei)rcsents   the  common  form  termed 
184,  are  respectively  called  stock  and  block  shears, 


183 


185. 


circular  holes  of  considerable  size,  by  the  aid  of  an  ordinary  carpenters'  brace ;  a  is  a 
thumb-screw;  6,  a  bar  of  |-in.  square  steel;  c,  cutting  edge,  which  may  be  modified 
to  suit  the  material  under  treatment ;  d,  pivot. 


120 


Sheet-Metal  Working. 


Flattening  Tooh. — Fig.  190  is  a  flattening  mill  for  sheet  metal;  and  Fig.  191  is  a 
pair  of  tinmen's  rolls. 

Folding  Tools. — Fig.  192  is  a  folding  or  hatchet  stake,  which  may  be  replaced  by  a 
strip  of  iron  with  a  sharp  edge,  over  which  the  margins  of  sheets  are  bent.    Fig.  193  is 


186. 


187. 


W:::3 


188. 


a  taper  stake  used  for  folding  tubes  of  tapering  form  ;  a  parallel  stake  is  also  required 
for  cylinders.  Fig.  194  is  a  pair  of  folding  rollers.  Fig.  195  is  a  machine  for  turning 
over  edges  and  running  a  whe  through  the  rim  formed  to  give  it  strength.     Fig.  196  is 


Sheet-Metal  "Working. 


121 


a  machine  for  closing  the  bottoms  of  vessels.  Fig.  197  is  a  burring  machine.  Fig.  198 
is  a  tea-kettle  bottom  stake:  Fig.  199,  a  funnel  stake  ;  Fig.  200,  a  side  stake  ;  Fig.  201, 
a  tinmen's  and  braziers'  horse ;  Fig.  202,  a  saucepan  belly  stake. 


189. 


102 


ISl. 


193. 


Forming  Tools. — Fig.  203  is  an  iron  or  boxwood  block  recessed  in  the  centre,  by  which 
Clips  or  dishes  of  copper  and  tin  maybe  shaped  in  one  piece.  Fig.  204  is  a  fluting  block, 
which  is  used  on  the  same  principle  to  make  corrugated  patterns.     When  extensive 


122 


Sheet-Metal  Working. 


194. 


195. 


^=^=^^3 


193. 


;l 


Sheet-Metal  Wokking. 


123 


203. 


202. 


204. 


203. 


203. 


20G. 


VBZO 


124 


Sheet-Metal  Working. 


operations  are  carried  on,  machines  replace  these  simple  contrivances.  Fig.  205  is  a  small 
and  Fig.  206  a  large  swaging  machine  ;  Fig.  207  is  a  grooving  machine.  Fig.  208  is  a 
creasing  iron;  Fig.  209,  a  block  hammer;  Fig.  210,  a  concave  hammer;  Fig.  211,  a 
rivet  set;  Fig.  212,  a  groove  punch;  Fig.  213,  a  hollow  prmch  ;  Fig.  214,  a  teapot 
neck  tool ;  Fig.  215,  a  kettle  lid  swage. 


209.  210. 


212.  213.  2U 


215. 


Working  the  Metals.— Tiiere  arc  3  distinct  ways  of  working  sheet  metal  into 
objects  of  use  or  ornament,  characterized  by  the  manner  of  securing  continuity  of  surface 
and  absence  of  holes  :  these  may  be  termed  seamless,  soldered,  and  riveted  goods. 

Seamless  Goods. — Some  metals,  especially  copper  and  block  tin,  lend  themselves  so 
well  to  hammering  processes,  and  manifest  sucli  a  tendency  to  assume  various  bent  forms 
withijut  either  creasing  or  cracking,  under  the  inliueuce  of  repeated  blows  judiciously 
delivered,  that  this  is  the  general  way  of  working  with  them.  The  piece  of  sheet  metal 
of  the  required  size  is  placed  on  the  mould  whose  form  it  is  to  acquire,  and  very  care- 
fully, gradually,  and  equally  hammered  till  it  assumes  the  desired  shape.  The  metal 
appears  to  have  the  iwwer  of  redistributing  its  constituent  molecules,  so  that  the  portion 
expanded  by  the  blows  draws  upon  the  unhammered  parts  and  maintains  a  uniform 
thickness.  A  hemispherical  bowl  may  be  made  in  this  way  from  a  ilat  sheet  by  gradu- 
ally beating  it  into  the  recess  in  Fig.  203  by  means  of  the  round  end  of  the  mallet.  A 
dish  with  fluted  sides  may  be  formed  from  another  sheet  by  hammering  a  margin  of  tlio 
same  width  as  tlie  desired  sides  in  the  hollows  of  Fig.  204,  the  bottom  of  the  dish  being 
subsequently  flattened  down  by  hammering  a  hard  block  on  it.  Obviously  tlie  process 
must  be  gradual  and  tlie  blows  equally  distributed  in  order  to  secure  symmetry  in  the 
finished  article.  Highly  ornamental  work  maybe  done  with  suitable  moulds  and  dies; 
but  in  the  case  of  copper,  if  the  impressions  are  deep,  the  metal  will  require  frequent 
annealing  by  beating  it,  as  the  blows  or  stamps  rapidly  render  it  brittle  and  liable  to 
crack. 

There  is  another  kind  of  seamless  work  produced  by  a  spinning  process.  The  metal 
or  rather  alloy  best  adapted  to  it  seems  to  be  Britannia  metal  or  pewter.  A  sheet  of 
this  metal  is  mounted  in  a  lathe,  either  by  drilling  a  hole  through  and  screwing  it,  or 
by  pinching  it  between  wooden  blocks.  When  fixed  so  that  it  can  rotate  freely,  pressure 
is  applied  to  the  side  of  the  plate  by  means  of  an  oiled  or  greased  burnishing  tool  with 
a  smooth  blunt  surface,  the  curve  in  the  sheet  increasing  as  the  pressure  is  augmented. 
In  this  way  a  circular  cup  is  gradually  produced  without  the  least  sign  of  a  crease  or 
inequality  in  the  surface.  By  using  sectional  moulds  capable  of  being  taken  to  pieces, 
most  complicated  patterns,  such  as  teapots,  feet  of  candlesticks,  &c.,  can  be  made,  by  gradu- 
ally pressing  the  rotating  metal  till  it  tightly  embraces  the  mould,  which  is  then  removed. 
More  elastic  metals  may  be  used  if  duly  annealed,  provided  they  possess  sufficient 
malleability. 

Seamed  Goods. — Seamed  goods,  whether  to  be  soldered  or  riveted,  may  be  described 
under  one  head,  as  they  differ  only  in  the  manner  of  securing  the  seam. 

Pipes. — These  are  among  the  simplest  articles  constructed  out  of  sheet  metal.     The 


Sheet-Metal  Working. 


125 


strip  must  be  cut  according  to  the  directions  already  given  for  cylinders,  idlowing 
sufHcient  margin  for  tlie  joint,  wliatevcr  kind  may  be  chosen.  The  strip  is  then  bent 
throughout  its  length  into  a  tubular  form  by  encircling  it  around  a  stout  circular  pole  of 
suitable  dimensions,  and  the  seam  made  in  one  of  the  methods  illustrated  in  Fi"-.  216. 

It  should  be  stated,  however,  that  in  the  case  of  the  bent  joints,  the  edges  must  bo 
turned  before  bending  the  slicet  into  a  cylinder  ;  this  is  effected  by  haramerin"-  the  ed"G 
over  the  hatchet  stake  with  a  mallet.     In  Fig.  216,  a  is  a  simple  lapped  joint  adapted  for 

216. 


articles  demanding  no  great  strength,  and  secured  by  soldering  down  the  edge ;  in  6, 
the  2  edges  are  hooked  into  each  other,  as  it  were,  then  hammered  down  and  soldered  ; 
in  c,  an  extra  strip  is  liooked  into  the  2  edges,  hammered  down  to  assume  the  form  shown 
ill  d  by  means  of  the  punch  e,  and  secured  by  thin  soldering  inside.  These  joints  all 
refer  to  tinned  iron  (tiu  plate) ;  in  the  case  of  copper  and  brass  the  edges  would  only  abut 
instead  of  overlapping.  Sheet  zinc  may  be  bent  to  any  desired  shape,  but  will  not 
retain  the  acquired  form  unless  it  is  heated  to  a  temperature  not  exceeding  that  of  boilin"- 
water,  say  200°  to  212°  F.  (93°  to  100°  C).  Sheet  brass  may  be  cut  and  worked  like 
zinc  and  tin.  The  same  may  be  said  of  lead,  which,  however,  has  too  little  rigidity  for 
many  purposes;  pewter  often  replaces  it  as  being  less  soft  and  capable  of  takino-  a 
polish. 

Cups. — Cups  differ  from  cylinders  in  the  addition  of  a  bottom  and  the  necessity  for 
strengthening  the  upper  edge  or  rim.  The  sheet  is  set  out  as  already  described  to  form 
the  upright  or  sloping  sides,  with  allowance  for  a  lapped  joint,  and  a  disc  is  cut  out  for 
the  bottom  about  J  in.  too  large  all  round.  Before  converting  the  sheet  into  a  cylinder 
or  frustrum  of  a  cone,  tlie  margins  must  be  prepared.  The  upper  margin  is  provided 
with  a  rim  by  turning  down  about  i  in.  of  the  edge,  by  the  aid  of  a  mallet  and  hatchet 
stake,  in  such  a  manner  that  the  actual  edge  of  the  metal  shall  lie  quite  close  against 
the  outside  surface  of  the  article,  while  the  rim  retains  a  fullness  and  rotundity.  If  the 
article  is  of  a  size  to  require  this  rim  to  possess  considerable  strength  or  rigidity,  tliis 
feature  is  gained  by  enclosing  a  piece  of  wire,  of  suitable  gauge,  within  the  rim.  Care 
is  needed  to  make  the  turnover  of  the  same  width  exactly  all  round,  otherwise  the  rim 
will  present  an  uneven  surface.  Wiring  facilitates  the  operation  of  making  a  rim,  but 
has  sometimes  to  be  dispensed  with,  as,  for  instance,  when  a  cover  is  to  tit  tightly 
over — in  canisters  for  storing  goods,  for  example.  The  next  step  is  to  prepare  the  lower 
margin  for  receiving  the  bottom,  which  may  be  done  either  before  or  after  the  sheet 
(with  its  rim  formed  and  wired)  is  bent  to  a  cylindrical  form.  In  the  former  case,  the 
margin  is  held  on  the  hatchet  stake,  and  about  a  in.  is  hammered  out  at  right  angles  all 
round,  so  as  to  form  a  flange  or  foot  to  the  cylinder ;  in  the  latter  case,  the  perfected 
cylinder  is  slipped  over  a  round  bar  held  in  a  vice,  and  supported  with  the  lower  margin 
lasting  on  the  bar,  so  that  blows  with  a  hammer  on  the  outside  will  turn  the  margin 
slightly  outwards,  when,  the  bend  being  thus  commenced,  the  cylinder  is  stood  on  end, 
and  the  hammering  gradually  proceeded  with  till  a  riglit  angle  is  attained.  The  foot 
of  tlie  cylinder  may  either  be  turned  over  the  disc  forming  the  bottom,  or  it  may  have 
the  disc  turned  over  it  instead,  the  latter  being  the  easier  method.  To  make  a  folded 
seam,  with  the  bottom  turned  up  over  the  foot,  stand  the  cylinder  centrally  on  the  disc, 
and  mark  the  margin  extending  beyond  it.  Then  remove  tlio  cylinder  and  proceed  to 
turn  up  a  flange  on  the  disc  by  holding  it  on  a  flat  circular  surface  as  near  the  right  si^e 


126  Sheet-Metal  Working. 

as  possible,  and  gradually  hammering  it  down.  When  many  articles  of  the  same  size 
are  to  be  made,  a  hard  cylindrical  block  of  the  correct  dimensions  is  very  useful.  After 
the  disc  has  had  its  margin  turned  up  saucer-wise,  the  cylinder  is  replaced  in  it,  and 
the  margin  of  the  disc  is  closely  hammered  down  upon  the  foot  of  the  cylinder  ;  solder 
run  along  the  seam  completes  the  joint.  This  folded  joint  is  unsurpassed  for  strength, 
but  it  demands  more  metal  and  more  time  for  its  production,  and  hence  is  generally 
replaced  by  the  following  modification.  The  completed  cylinder,  without  any  foot  or 
flange  at  the  bottom  margin,  is  stood  on  the  disc,  which  has  already  been  converted  into 
a  saucer,  and  the  edge  of  this  saucer  is  soldered  to  the  upright  wall  of  the  cylinder 
all  round. 

Square  boxes. — The  sheets  to  form  boxes  and  trays  of  rectangular  shape  may  be  cut 
in  different  ways,  according  to  where  it  is  admissible  to  have  a  soldered  seam.  Thus 
the  bottom  may  be  made  separately  from  the  sides,  having  a  little  flange  turned  on  the 
mar"-in  to  be  attached  by  a  horizontal  seam  to  the  sides,  which  latter  may  consist  of  one 
long  strip,  bent  to  suit  the  corners  and  with  only  one  vertical  seam  to  join  the  2  ends ; 
or  the  bottom  and  sides  luay  be-all  in  one  piece,  with  triangular  slips  cut  out  at  the 
corners  to  allow  of  the  turning  up,  when  there  will  be  a  vertical  seam  at  each  corner, 
and  no  horizontal  seam. 

Eiveting. — This  simple  operation  consists  in  punching  holes  in  fhe  overlapping  sheet 
metal,  inserting  rivets  of  corresponding  composition,  and  hammering  out  the  ends  to 
form  second  heads.  A  riveted  joint  can  seldom  be  made  watertight ;  but  in  some  cases 
it  is  very  useful  on  the  score  of  its  strength,  and  inside  soldering  can  be  added  to  fill 
interstices  and  complete  the  joint. 

CARPENTRY. — The  term  "  carpentry  "  is  here  employed  in  its  widest  sense, 
embracing  what  is  more  properly  known  as  "joinery."  The  former  is  strictly  applied  to 
the  use  of  wood  in  architectm-al  structures,  as  for  instance  the  joists,  flooring,  and 
rafters  of  a  house,  while  the  latter  refers  to  the  conversion  of  wood  into  articles  of 
utility  which  are  not  remarkable  for  beauty  of  design  or  delicacy  of  finish.  It  is  eminently 
convenient  to  discuss  the  united  arts  of  carpentry  and  joinery  under  a  single  head,  as 
they  are  really  so  closely  connected  as  to  present  no  real  difference. 

The  art  of  the  carpenter  may  be  divided  into  3  distinct  heads — (1)  a  consideration 
of  the  kinds,  qualities,  and  properties  of  the  woods  to  be  worked  upon  ;  (2)  a  description 
of  the  tools  employed,  and  how  to,  use  them  and  keep  them  in  order;  and  (3)  the 
rudimentary  principles  of  constructing  fabrics  in  wood,  with  examples  showing  their 
application  in  various  ways.     The  subject  will  be  dealt  with  in  this  order. 

Woods. — It  will  be  well  to  begin  with  an  enumeration  of  the  woods  used  in 
carpentry — (other  woods  will  be  found  described  under  the  arts  in  which  they  are  used, 
e.  g.  Carving) — leaving  such  matters  as  relate  to  all  woods  in  general  till  afterwards. 
They  will  be  arranged  in  alphabetical  order.  The  terms  used  in  describing  the 
characters  of  the  various  woods  may  be  explained  once  for  all.  The  "  cohesive  force  " 
is  the  weight  required  to  pull  asunder  a  bar  of  the  wood  in  the  direction  of  its  length ; 
the  figures  denoting  the  strength,  toughness,  and  stiffness,  are  in  comparison  with  oak, 
which  is  taken  as  the  standard,  and  placed  at  100  in  each  case  ;  the  "crushing  force" 
is  the  resistance  to  compression;  the  "  breaking-weight  "  is  the  weight  required  to  brealv 
a  bar  1  in.  sq.  supported  at  two  i^oints  1  ft.  apart,  with  the  weight  suspended  in  the 
middle. 

Acacia  or  American  Locust-tree  (Rohinia  pseudo-acacia). — This  beautiful  tree,  of 
considerable  size  and  very  rapid  growth,  inhabits  the  mountains  of  America,  from  Canada 
to  Carolina,  its  trunk  attaining  the  mean  size  of  32  ft.  long  and  23  in.  (iiam.  The 
seasoned  wood  is  much  valued  for  its  durability,  surpassing  oak.  It  is  admirable  for 
building,  posts,  stakes,  palings,  treen-ails  for  ships,  and  otlier  purposes.  Its  weiglit  is 
49-56  lb.  a  cub.  ft. ;  cohesive  force,  10,000-13,000  lb. ;  and  the  strength,  stifihess,  and 
toughness  of  young  unseasoned  wood  are  respectively  95,  98,  and  92.     The  wood  is 


Caepentry — Woods.  127 

greenisli-ycllow,  ■with  reddish-brown  veins.  Its  structure  ig  alternately  neatly  compact 
and  very  porous,  distinctly  marking  the  annual  rings  ;  it  has  no  large  medullary  rays. 

Ake  (Ihdonea  viseosa). — A  small  tree,  6-12  ft.  high.  Wood  very  hard,  variegated 
black  and  white ;  used  for  native  clubs ;  abundant  in  dry  woods  and  forests  in  New 
Zealand. 

Alder  (Alnus  glutinosa). — This  small  tree  inhabits  -wet  grounds  and  river-banks  in 
Europe  and  Asia,  seldom  exceeding  40  ft.  high  and  2iin.  diam.  The  wood  is  extremely 
durable  in  water  and  wherever  it  is  constantly  wet ;  but  it  soon  rots  on  exposure  to  the 
weather  or  to  damp,  and  is  much  attacked  by  worms  when  dry.  It  is  soft,  works 
easily,  and  carves  well ;  but  it'is  most  esteemed  for  piles,  sluices,  and  pumps,  and  has  been 
much  cultivated  in  Holland  and  Flanders  for  such  purposes.  Its  weight  is  34-50  lb.  a 
cub.  ft. ;  cohesive  force,  5000-13,900  lb. ;  strength,  SO ;  stiffness,  63 ;  toughness,  101. 
The  wood  is  white  when  first  cut,  then  becomes  deep-red  on  the  surface,  and  eventually 
fades  to  reddish-yellow  of  different  shades.  The  roots  and  knots  are  beautifully  veined. 
It  is  wanting  in  tenacity,  and  shrinks  considerably.  The  roots  and  heart  are  used  for 
cabinet-work. 

Alerce-wood  (Callitris  quadrivalvis). — This  is  the  celebrated  citrus-wood  of  the 
ancient  Eomans,  the  timber  of  the  gum  sandarach  tree.  The  wood  is  esteemed  above 
all  others  for  roofing  temples  and  for  tables,  and  is  employed  in  the  cathedral  of  Cordova. 
Among  the  luxurious  Komans,  the  great  merit  of  the  tables  was  to  have  the  veins 
arranged  in  waving  lines  or  spirals,  the  former  called  "  tiger  "  tables  and  the  latter 
"  panther."  Others  were  marked  like  the  eyes  on  a  peacock's  tail,  and  otliers  agait 
appeared  as  if  covered  with  dense  masses  of  grain.  Some  of  these  tables  were  4-4J  ft. 
diam.  The  specimens  of  tlie  tree  now  existing  in  S.  Morocco  resemble  small  cypresses, 
and  are  a|3parently  shoots  from  the  stumps  of  trees  that  have  been  cut  or  burnt,  though 
possibly  their  stunted  habit  may  be  due  to  sterility  of  soil.  The  largest  seen  by  Hooker 
and  Ball  in  1S7S  were  in  the  Ourika  valley,  and  were  about  30  ft.  high.  The  stems  of 
the  trees  swell  out  at  the  very  base  into  roundish  masses,  half  buried  in  soil,  rarely 
attaining  a  diameter  of  4  ft.  It  is  tbis  basal  swelling,  whether  of  natural  or  artificial 
origin,  which  affords  the  valuable  wood,  exi^orted  in  these  days  from  Algiers  to  Paris, 
where  it  is  used  in  the  richest  and  most  expensive  cabinet-work.  The  unique  beauty 
of  the  wood  will  always  command  for  it  a  ready  market,  if  it  be  allowed  to  attain 
sufBcient  size. 

Alerse  {Libocedrus  tetragona). — This  is  a  Chilian  tree,  affording  a  timber  which  is 
largely  used  on  the  S.  Pacific  coast  of  America,  and  an  important  article  of  commerce. 
It  gives  spars  80-90  ft.  long,  and  800-1500  boards.  Its  grain  is  so  straight  and  even 
that  shingles  sj^lit  from  it  appear  to  have  been  planed. 

Apple  [Australian]  (^Angophora  suhvelutina). — The  so-called  apple-tree  of  Queensland 
yields  planks  20-30  in.  in  diameter,  the  wood  being  very  strong  and  durable,  and  much 
used  by  wheelwrights  and  for  ships'  timbers. 

Ash  (Fraxinus  excelsior). — The  common  ash  is  indigenous  to  Europe  and  N.  Asia, 
and  found  throughout  Great  Britain.  The  young  wood  is  more  valuable  than  the  old  ; 
it  is  durable  in  the  dry,  but  soon  rots  by  exposiu'e  to  damp  or  alternate  wetting,  and  is 
very  subject  to  worm  when  felled  in  full  sap.  It  is  difficult  to  work  and  too  flexible  for 
building,  but  valuable  in  machinery,  wheel-carriages,'  blocks,  and  handles  of  tools. 
The  weight  is  34-52  lb.  a  cub.  ft.;  cohesive  force,  0300-17,000  lb.  ;  strength,  119; 
stiffness,  89  ;  toughness,  160.  The  colour  of  the  wood  is  brownish-white,  with  longi- 
tudinal yellow  streaks ;  the  annual  layers'  are  separated,  by  a  ring  full  of  pores.  The 
most  striking  characteristic  possessed  by  ash  is  that  it  has  apparently  no  sapwood  at  all 
— thatjis  to  say,  no  difference  between  the  rings  can  be  detected  until  the  tree  is  very 
old,  when  the  heart  becomes  black.  The  wood  is  remarkably  tough,  elastic,  flexible, 
and  easily  worked.  It  is  economical  to  convert,  in  consequence  of  the  absence  of  sap. 
Very  great  advantage  is  found  in  reducing  ash  logs  soon  after  they  are  felled  into  plank 


128  Cakpentey — Woods. 

or  boarJ  for  seasoning,  since,  if  left  for  only  a  short  time  in  the  round  state,  deep  shakes 
open  from  the  surface,  which  involve  a  very  heavy  loss  when  brought  on  later  for 
conversion.  Canadian  and  American  ash,  of  a  reddish-white  colour,  is  imported  to  this 
country  chiefly  for  making  oars.  These  varieties  have  the  same  characteristics  as  English 
ash,  but  are  darker  in  colour.     The  Canadian  variety  is  the  better  of  the  two. 

Assegai-wood  or  Cape  Lancewood  {Curtisia  fag Inea).— This  tree,  the  oomUehe  of  the 
African  natives,  gives  a  very  tough  wood,  used  for  wheel-spokes,  shafts,  waggon-rails, 
spears,  and  turnery,  weighing  5G  lb.  a  cub.  ft. 

Beech  {Fagus  mjlvatica). — The  common  beech  inhabits  most  temperate  parts  of 
Europe,  from  Norway  to  tlic  Mediterranean,  and  is  plentiful  in  S.  Russia.  It  is  most 
abundant  in  the  S.  and  Midland  counties  of  England,  growing  on  chalky  soils  to  100  ft. 
liigh  and  4-6  ft.  diam.  Wood  grown  in  damp  valleys  becomes  brittle  on  drying ;  it  is  very 
liable  to  destruction  by  worms,  decays  in  damp  situations,  less  in  a  dry  state,  but  least  of 
■all  when  constantly  under  water.  It  is  thus  most  useful  for  piles,  and  for  knees  and 
planking  of  sliips.  Its  uniform  texture  and  hardness  make  it  very  valuable  for  tools  and 
common  furniture.  It  is  also  used  for  carriage-panels  and  wooden  tramways.  Its  weight 
is  43-53  lb.  a  cub.  ft. ;  cohesive  force,  6070-17,000  lb. ;  strength,  103 ;  stiffness,  77 ; 
toughness,  13S. 

Beech  [American]. — Two  species  of  Fagus  are  common  in  N.  America, — the  white 
(JF.  sylvestris),  and  the  red  {F.  ferruginea).  The  perfect  wood  of  the  former  is  frequently 
only  8  in.  in  a  trunk  18  in.  diam.,  and  it  is  of  little  use  except  for  fuel.  The  wood  of 
the  latter,  which  is  almost  exclusively  confined  to  the  N.-E.  States,  Canada,  New 
Brunswick,  and  Nova  Scotia,  is  stronger,  tougher,  and  more  compact,  but  so  liable  to 
insect  attacks  as  to  be  little  used  in  furniture ;  yet  it  is  very  durable  when  constantly 
immersed  in  water. 

Beech  [Australian]  (Gmelina  Leichhardlii)  attains  a  height  of  SO  to  120  ft.  and  yields 
planks  24  to  42  in.  wide ;  its  wood  is  valuable  for  decks  of  vessels,  &c.,  as  it  is  said 
neither  to  expand  nor  contract,  and  is  exceedingly  durable.  It  is  worth  100s.  to  120s. 
per  1000  ft.  super. 

Birch  {Betula  spp.). — The  common  birch  (B.  alba)  is  less  important  as  a  source  of 
wood  than  as  affording  an  empyreumatic  oil.  Its  wood  is  neither  strong  nor  durable, 
but  is  easily  worked,  moderately  hard,  and  of  straight  and  even  grain,  rendering  it 
useful  for  chair-making,  cabinet-making,  and  light  turnery.  The  American  red  birch 
{B.  rubra)  has  similar  uses.  The  black  or  cherry  birch  {B.  lenta  [iiigraj)  of  N.  America 
is  superior  to  all  others,  and  imported  in  logs  6-20  ft.  long  and  12-30  in.  diam.  for 
furniture  and  turnery.  Quebec  birch  is  worth  31.  5s.-4L  15s.  a  load.  There  is  a  so-called 
"  yellow  birch  "  in  Newfoundland,  known  also  as  "  witch-hazel." 

Birch  [White  or  Black-heart]  {Fagus  solandri). — A  lofty,  beautiful  evergreen  tree  100 
ft.  high,  trunk  4-5  ft.  diameter.  The  heart  timber  is  darker  than  that  of  Fagus  fusca 
and  is  very  durable.  This  wood  is  well  adapted  for  fencing  and  bridge  piles.  The 
tree  occurs  only  in  the  southern  part  of  the  North  Island  of  New  Zealand,  but  is 
abundant  in  tlie  South  Island  up  to  5000  ft. 

Blackwood  (A<'acia  melanoxijlon)  is  one  of  the  most  valuable  Australian  woods.  It  is 
extensively  used  in  tiie  construction  of  railway  carriages,  and  is  well  adapted  for  light 
and  heavy  framing  purposes,  gun-stocks,  coopers'  staves,  and  turners'  work,  and  in  this 
respect  contrasts  favourably  with  most  of  the  English  woods ;  and,  from  the  facility  with 
which  it  is  bent  into  the  most  difHcult  curves,  it  is  highly  prized  for  buggy  and  gig 
shafts,  &c.  Within  tlic  last  few  years  it  has  been  introduced  extensively  into  the  manu- 
facture of  the  finer  description  of  furniture,  such  as  drawing-room  suites,  and  is  found 
far  superior  to  walnut,  owing  to  its  strength  and  toughness.  Blackwood  resembles 
in  figure  different  woods,  such  as  walnut,  mahogany,  rosewood,  zebrawood,  &c. 
Formerly  mahogany  was  extensively  imported  for  the  purpose  of  manufacturing  billiard 
tables;   but   at  the  present  time  blackwood  has  taken  the  place  of  mahogany  in  the 


Carpentry — Woods.  121} 

above-named  mnnufacture.  It  is  pronounced  to  be  far  superior  to  the  best  Spanisli 
mahogany  for  this  purpose  ;  owing  to  its  density  and  resisting  qualities,  it  is  actcil 
on  very  sliglitly  by  tlie  clianges  of  weather,  and  is  capable  of  taking  a  fine  polish. 
It  is  named  from  the  dark-brown  colour  of  the  mature  wood,  which  becomes  black 
when  washed  with  lime-water.  In  moist  shaded  localities,  the  tree  grows  more 
rapidly,  and  the  wood  is  of  a  much  lighter  colour ;  hence  this  variety  is  called 
"Lightwood"  in  Hobart  Town,  to  distinguish  it  from  the  other.  Diameter,  IJ  to 
4  ft.;  average,  about  2\  ft.  ;  height,  CO  to  130  ft.;  sp.  grav.,  about  0-855.  Found 
throughout  Tasmania,  but  not  abundantly  in  any  one  locality.  Price,  about  12s.  to 
14s.  per  100  ft.  super.,  in  the  log. 

Box  (Buxus  sempervirens). — The  common  evergreen  box  is  a  native  of  Europe  as 
far  as  52°  N.  lat.,  and  is  abundant  in  S.  and  E.  France,  Spain,  Italy,  the  Black 
Sea  coast,  Persia,  N.  India,  China,  and  Japan.  For  some  years  past  the  supply  of  this 
important  wood  has  diminished  in  quantity  and  risen  in  price.  It  is  mainly  derived  from 
the  forests  of  the  Caucasus,  Armenia,  and  the  Caspian  shores.  The  wood  of  the 
best  quality  comes  from  the  Black  Sea  forests,  and  is  principally  shipped  from  the 
port  of  Poti.  The  produce  of  the  Caspian  forests  known  in  the  trade  as  "  Persian,"  used 
also  to  be  exported  through  the  Black  Sea  from  Taganrog.  This  found  its  way,  after 
the  commencement  of  the  Kusso-Turkish  war,  via  the  Volga  canal,  to  St.  Petersburg. 
The  produce  of  the  Caspian  foj-ests  is  softer  and  inferior  in  quality  to  that  of 
the  Black  Sea.  It  is  a  large  article  of  trade  with  Eussia,  reaching  Astrakhan  and 
Nijni-Novgorod  in  the  sjiring,  and  being  sold  during  the  fair.  It  recently  amounted  to 
130,000  poods  (of  36  lb.).  True  Caucasian  boxwood  may  be  said  to  be  commercially 
non-existent,  almost  every  marketable  tree  having  been  exported.  The  value  of  the  yet 
unworked  Abkhasian  forests  has  been  much  exaggerated,  many  of  the  trees  being  either 
knotted  or  hollow  from  old  age,  and  most  of  the  good  wood  having  been  felled  by  the 
Abkhasians  previous  to  Russian  occupation.  The  boxwood  at  present  exported  from 
Eostov,  and  supposed  to  be  Caucasian,  comes  from  the  Persian  provinces  of  Mazanderan 
and  Ghilan,  on  the  Caspian.  Boxwood  is  characterized  by  excessive  hardness,  great 
weight,  evenness  and  closeness  of  grain,  light  colour,  and  capacity  for  taking  a  fine 
polish.  Hence  it  is  very  valuable  for  wood-engraving,  turning,  and  instrument-making. 
The  Minorca  box  (B.  halearica),  found  in  several  of  the  Mediterranean  islands,  and  in 
Asia  Minor,  yields  a  similar  but  coarser  wood,  which  probably  finds  its  way  into  com- 
merce.    The  approximate  value  of  Turkey  box  is  Q-201.  a  ton. 

Box  [Australian]  (Tristania  confertci)  grows  in  Queensland  to  10  ft.  in  height,  and 
35-50  in.  in  diameter ;  the  wood  is  invaluable  for  ship-building,  ribs  of  vessels  made 
from  it  having  been  known  to  last  unimpaired  upwards  of  30  years. 

Box  [Spurious]  {Eucalyptus  leucoxijlon)  is  a  valuable  Victorian  timber,  of  a  light-grey 
colour  and  greasy  nature,  remarkable  for  the  hardness  and  closeness  of  its  grain,  great 
strength,  tenacity,  and  durability  both  in  the  water  and  when  placed  on  the  groimd.  It 
is  largely  used  by  coachmakers  and  wheelwrights  for  the  naves  of  wheels  and  for  heavy 
framing,  and  by  millwrights  for  the  cogs  of  their  wheels.  In  ship-building  it  has 
numerous  and  important  applications,  and  forms  one  of  the  best  materials  for  treenails, 
and  for  working  into  large  screws  in  this  and  other  mechanical  arts. 

Tlie  Grey  Box  {_E.  dealbata']  is  another  species,  used  for  similar  purposes  to  the 
preceding, 

Broadleaf  {Griselinia  littoralis). — An  erect  and  thickly  branched  bush  tree,  50-60  ft. 
high;  trunk  3-10  ft.  diam.  Wood  splits  freely,  and  is  valuable  for  fencing  and  in  ship- 
building ;  some  portions  make  handsome  veneers.  Grows  chiefly  in  the  South  Island 
of  New  Zealand  and  near  the  coasts. 

Broadleaf  or  Almond  (Terminal ia  latifolia). — This  is  a  Jamaica  tree,  growing  6.0  ft 
high  to  the  main  branches,  and  3§-5  ft.  diam.  It  is  used  for  timbers,  boards,  shingles,  and 
staves.     Its  weight  is  48  lb.  a  cub.  ft. ;  crushing-force,  7500  lb. ;  breaking-weight,  750  lb. 


130  Oarpentet — Woods. 

Bullet-trce  (Mimusops  Balaia). — This  tree  is  found  in  the  W.  Indies  and  Central 
America.  Its  wood  is  very  hard  and  durable,  and  iitted  for  most  outside  work ;  it  is 
used  principally  for  posts,  sills,  and  rafters.  It  warps  much  in  seasoning,  splits  easily, 
becomes  slippery  if  used  as  flooring,  and  is  very  liable  to  attacks  of  sea-worms.  Its 
weight  is  65i  lb.  a  cub.  ft. ;  crushing-force,  14,330  lb. 

Bunya-bunya  {Araucaria  Bidicillii)  grows  to  the  height  of  100-200  ft.,  and  attains 
a  diameter  of  30-48  in.  This  noble  tree  inhabits  the  scrubs  in  tlie  district  between  the 
Brisbane  and  the  Burnett  rivers,  Queensland,  and  in  the  27th  parallel  it  extends  over  a 
tract  of  country  about  30  miles-in  length  and  12  in  breadth.  The  timber  is  strong  and 
good,  and  full  of  beautiful  veins,  works  with  facility,  and  takes  a  high  polish. 

Cedar  [Australian  Red]  (Cedrela  australis). — This  tree  is  a  native  of  Australia,  where 
it  has  been  almost  exterminated,  the  timber  being  found  so  useful  in  house-building  (for 
joinery,  doors,  and  sashes)  and  boat-building.  Its  weight  is  35  lb.  a  cub.  ft. ;  breaking- 
weight,  471  lb. 

Cedar  [Bermuda]  (Junijierus  hermudiana). — This  species  is  a  native  of  the  Bermudas 
and  Bahamas.  Its  wood  much  resembles  that  of  Virginian  Cedar,  and  is  used  fct 
similar  purposes,  as  well  as  for  ship-building.  It  is  extremely  durable  when  ventilated 
and  freed  from  sapwood.  It  lasts  150-  200  years  in  houses,  and  40  years  as  outside  ship- 
planking.     It  is  diiEcult  to  get  above  8  in.  sq.     Its  weight  is  46-47  lb.  a  cub.  ft. 

Cedar  [Lebanon]  (Abies  Cedrus  {_Cedrus  LibaniJ). — This  evergreen  tree  is  a  native  of 
Syria,  and  probably  Candia  and  Algeria.  The  trimk  reaches  50  ft.  high  and  34-39  in. 
diam.  The  wood  is  said  to  be  very  durable,  and  to  have  been  formerly  extensively  used 
in  the  construction  of  temples.  It  is  straight-gramed,  easily  worked,  readily  splits,  and 
is  not  liable  to  worm.  Its  weight  is  30-38  lb.  a  cub.  ft. ;  cohesive  force,  7400  lb.  a  sq. 
in. ;  strength,  C2  ;    stiffness,  28  ;  toughness,  106. 

Cedar  [New  Zealand]  (Libocedrus  Doniana  and  L.  Bidwillii). — Of  the  species,  the 
former,  the  Icawaka  of  the  natives,  is  a  fine  timber  tree  60-100  ft.  high,  yielding  heavy 
fine-grained  wood,  useful  in  fencing,  house-blocks,  piles,  and  sleepers.  It  weighs  30  lb. 
a  cub.  ft. ;  breaking-weight,  400  lb.  The  wood  runs  3  to  5  ft.  in  diameter,  and  is 
reddish  in  colour  ;  it  is  used  by  the  Maoris  for  carving,  and  is  said  to  be  excellent  for 
planks  and  spars.  The  second  species,  called  pahantea  by  the  natives,  reaches  60  to 
80  ft.  high  and  2  to  3  ft.  in  diameter.  In  Otago  it  produces  a  dark-red  free-working 
timber,  rather  brittle,  chiefly  adapted  for  inside  work.  The  timber  has  been  used  for 
sleepers  on  the  Otago  railways  of  late  years,  and  is  largely  employed  for  fencing 
purposes,  being  frequently  mistaken  for  Totara. 

Cedar  [Virginian  Eed]  {Juniperus  virginiana). — This  small  tree  (45  to  50  ft.  high  and 
8  to  18  in.  in  diameter)  inhabits  dry  rocky  hillsides  in  Canada,  the  United  States,  and  W. 
Indies,  'and  flourishes  in  Britain.  The  wood  is  mucli  used  in  America  for  wardrobes, 
drawers,  boxes,  and  furniture,  being  avoided  by  all  insects  on  account  of  its  strong 
odour  and  flavour.  It  is  light,  brittle,  and  nearly  uniform  in  texture.  It  is  very 
extensively  employe<l  for  covering  graphite  pencils,  being  imported  in  logs  6-10  in.  sq. 
It  weighs  40|  lb.  a  cub.  ft.  The  heartwood  is  reddish-brown,  the  sapwood  is  white, 
straight-grained,  and  porous.  It  possesses  about  %  the  strength  of  red  pine,  is 
easily  worked,  shrinks  little,  and  is  very  durable  when  well  ventilated.  A  resinous 
exudation  makes  freshly-cut  timber  hard  to  work. 

Cedar  [W.  Indian  or  Havanna]  {Cedrela  odorata). — This  tree  is  a  native  chiefly  of 
Honduras,  Jamaica,  and  Cuba,  having  a  stem  70  to  80  ft.  high  and  3  to  5  ft.  diam.,  and 
exported  in  logs  up  to  3-4  ft.  sq.  Its  wood  is  soft,  porous,  and  brittle,  and  used  chiefly 
for  cigar-boxes  and  the  inside  of  furniture.  It  makes  durable  planks  and  shingles.  Its 
weight  is  36  lb.  a  cub.  ft. ;  crushing-weight,  6600  lb. ;  breaking-weight,  400  lb.  The 
approximate  London  market  values  are  4-5^d.  a  ft.  for  Cuba  cedar,  and  4-6jd.  for 
Honduras,  &c. 

Ceda    Boom  (JViddringtonia  juniperoides), — This  tree  is  found  in  N.  and  W.  Cape 


Caepentry — Woods.  131 

■Colony,  and  its  wood  is  used  for  floors,  roofs,  and  other  building  puriioscs,  but  will  not 
stand  the  weather. 

Cherry  [Australian]  (Exocarpus  cupressiformis')  is  a  soft,  fine-grained  timber,  and 
forms  the  best  Australian  wood  for  carving.  It  reaches  a  height  of  20-30  ft.,  and  a 
diameter  of  9-15  in. ;  its  sp.  gr.  is  about  0*785.  It  is  used  for  tool-handles,  spokes,  gun- 
stocks,  &c. 

i  Chestnut  (Castanea  vesca). — This,  the  sweet  or  Spanish  chestnut,  is  said  to  be  a 
native  of  Greece  and  W.  Asia,  but  grows  wild  also  in  Italy,  France,  Spain,  N.  Africn, 
and  N.  America.  It  lives  to  1000  years,  but  reaches  its  prime  at  about  50,  when  the  stem 
may  be  40-60  ft.  long  and  3-6  ft,  diam.  The  wood  is  hard  and  compact:  when  young, 
it  is  tough  and  flexible,  and  as  durable  as  oak ;  when  old,  it  is  brittle  and  shaky.  It 
does  not  shrink  or  swell  so  much  as  other  woods,  and  is  easier  to  work  than  oak;  but 
soon  rots  when  built  into  walls.  It  is  valued  for  hop-poles,  palings,  gate-posts,  stakes, 
and  similar  purposes.  Its  weight  is  43-54  lb.  a  cub.  ft. ;  cohesive  force,  8100  lb.  ; 
strength,  GS ;  stiffness,  54 ;  toughness,  85.  The  wood  much  resembles  oak  in  appear- 
ance, but  can  be  distinguished  by  having  no  distinct  large  medullary  rays.  The  annual 
rings  are  very  distinct ;  the  wood  has  a  dark-brown  colour;  the  timber  is  slow  of  growth, 
and  there  is  no  sapwood. 

Cypress  (fiupressus  sempervirens). — This  tree  is  abundant  in  Persia  and  the  Levant, 
and  cultivated  in  all  countries  bordering  the  Mediterranean,  thriving  best  in  warm  sandy 
or  gravelly  soil,  and  reaching  70-90  ft.  high.  Its  wood  is  said  to  be  the  most  durable  of 
all.  For  furniture,  it  is  stronger  than  mahogany,  and  equally  repulsive  to  insects.  In 
Malta  and  Candia,  it  is  much  used  for  building.     It  weighs  about  40-41  lb.  a  cub.  ft. 

Cypress  pine  (Callitris  columellaris)  is  a  plentiful  tree  in  Queensland,  attaining  a 
diameter  of  40  in.  It  is  in  great  demand  for  piles  and  boat-sheathing,  as  it  resists  the 
attacks  of  cobra  and  white  ants.  The  wood  is  worth  120s.  per  1000  ft.  super.  The  roots 
give  good  veneers. 

Dark  yellow  wood  (Rhus  rliodanthema)  grows  in  Queensland  to  a  moderate  size, 
affording  planks  up  to  24  in.  wide ;  the  wood  is  soft,  fine-grained,  and  beautifully 
marked,  and  is  highly  esteemed  for  cabinet  work,  being  worth  100  to  120s.  per  1000  ft. 
super. 

Deal  [White],  White  Fir,  or  Norway  Spruce  (Abies  excelsa). — This  tree  inhabits  the 
mountainous  districts  of  Europe,  and  extends  into  N.  Asia,  being  especially  prevalent  in 
Norway.  It  runs  to  80-100  ft.  high,  and  about  2-3  ft.  max.  diam.  The  tree  requires 
70-80  years  to  reach  perfection,  but  is  equally  durable  at  all  ages.  It  is  much  imported 
in  spars  and  deals,  the  latter  about  12  ft.  long,  3  in.  thick,  and  9  in.  wide.  The  wood 
glues  well,  and  is  very  durable  while  dry,  but  much  more  knotty  than  Northern  Pine. 
It  is  fine-grained  and  does  well  for  gilding  on,  also  for  internal  joinery,  lining  furniture, 
and  packing-cases.  A  principal  use  is  for  scaffolds,  ladders,  and  masts,  for  which 
purpose  it  is  largely  imported  from  Norway  in  entire  trunks,  30-60  ft.  long,  and  (j-S  in. 
max.  diam.  It  is  shipped  from  Christiania,  Friedrichstadt,  Drontheim,  Gottenburg, 
Riga,  Narva,  St.  Petersburg,  &c.  Christiania  deals  and  battens  are  reckoned  best  for 
panelling  and  upper  floors ;  Friedrichstadt  have  small  black  knots ;  lowland  Norway 
split  and  warp  in  drying ;  Gottenburg  are  stringy  and  mostly  used  for  packing-cases ; 
Narva  are  next  in  quality  to  Norway,  then  Riga;  St.  Petersburg  shrink  and  swell  even 
after  painting.  The  wood  is  generally  light,  elastic,  tough,  easily  worked,  and  extremely 
durable  when  properly  seasoned.  It  weighs  28-34  lb.  a  cub.  ft. ;  cohesive  force, 
SOOO-12,000  lb.  a  sq.  in.  ;  strength,  104  ;  stiffness,  104;  toughness,  104.  The  wood  is 
yellowish-white  or  brownish-red,  becoming  bluish  by  exposure.  The  annual  rings  are 
clearly  defined,  the  surface  has  a  silky  lustre,  and  the  timber  contains  many  hard  glossy 
knots.  It  is  soft,  warps  much  unless  restrained  while  seasoning,  and  lacks  durability  ; 
it  is  weaker  than  red  and  yellow  pine,  less  easily  worked,  and  apt  to  snap  under  a  sudden 
load.    It  is  a  nice  wood  for  dresser-tops,  shelves,  and  common  tables,  but  should  not  be 

K  2 


132  Carpentry — Woods. 

less  than  1  in.  thick,  on  account  of  warping.     The  knots  are  liable  to  turn  the  plane- 
iron. 

Dcndax  (Cedrus  Deodara). — This  tree  is  found  in  the  Himalayas  at  5000-12,000  ft., 
and  on  the  higher  mountains  from  Nepal  to  Kashmir,  measuring  150-200  ft.  high,  and 
over  30  ft.  circ.  Its  wood  is  extremely  valuable  for  all  carpentry,  and  most  generally 
used  in  the  Punjab  for  building.  Its  weight  is  37  lb.  a  cub.  ft. ;  breaking-weight, 
520  lb. 

Dogwood. — The  American  dogwood  (Cornus  florida)  is  a  tree  30  ft.  high,  common  in 
the  woods  of  many  parts  of  N.  America.  Its  wood  is  hard,  heavy,  and  close-grained,  and 
largely  used  locally  for  tool-handles  ;  it  has  been  imjiorted  into  England  with  some  success 
as  a  substitute  for  box  in  making  shuttles  for  textile  machinery.  The  black  dogwood  or 
alder  buckthorn  (Rhamnus  Frangula)  is  abundant  in  Asia  Minor,  and  affords  one  of  the 
best  wood  charcoals  for  gunpowder-making.  The  principal  uses  made  of  Bahama  dog- 
wood (Piscidia  Erythrina)  are  for  fellies  for  wheels  and  for  ship  timber.  From  its 
toughness  and  other  properties,  it  is  better  adapted  to  the  former  purpose  than  any  other 
of  the  Bahamian  woods.  The  tree  does  not  attain  any  considerable  size,  and  is  generally 
crooked ;  a  rather  soft,  open-grained,  but  very  tough  wood. 

Doom  or  Kameel  Boom  {Acacia  horrida). — Tliis  tree  is  a  native  of  S.  Africa,  and 
affords  small  timber  used  for  fencing,  spars,  fuel,  and  charcoal. 

Ebony  {Diospijros  spp.}. — The  best  and  most  costly  kind  of  ebony,  having  the 
blackest  and  finest  grain,  is  the  wood  of  D.  reticulata,  of  Mauritius.  The  E.  Indian 
species,  D.  Melanoxylon  and  D.  Ehenaster,  also  contribute  commercial  supplies,  and 
another  kind  is  obtained  from  D.  Ehenum,  of  Ceylon.  The  heartwood  of  the  trunk  of 
these  trees  is  very  hard  and  dense,  and  is  largely  used  for  fancy  cabinet-making,  mosaic 
work,  turnery,  and  small  articles.  The  approximate  London  market  values  are  5-20Z.  a 
ton  for  Ceylon,  and  3-12Z.  for  Zanzibar,  &c. 

'EA.m  (JJlmus  spp.). — Five  species  of  elm  are  now  grown  in  Britain: — The  common 
rough-leaved  {U.  campestrin)  is  frequent  in  scattered  woods  and  hedges  in  S.  England, 
and  in  France  and  Spain,  attaining  70-80  ft.  high,  and  4  ft.  diam.    Its  wood  is  harder  and 
more  durable  than  the  other  kinds,  and  is  preferred  for  coffins,  resisting  moisture  well. 
The  corked-barked  ( Z3''.  subcrosa)  is  common  in  Sussex,  but  the  wood  is  inferior.  The  broad- 
leaved  wych-elm  or  wych-hazel  (K  montami)  is  most  cultivated  in  Scotland  and  Ireland, 
reaching  70-80  ft.  high  and  3-4§  ft.  diam.     The  smooth-leaved  wych-elm  (Z7.  glabra)  is 
abundant  in  Essex,  Hertford,  the  N.  and  N.-E.  counties  of  England,  and  in  Scotland, 
growing  to  a  large  size.     The  wood  is  tough  and  flexible,  and  preferred  for  wheel-naves. 
The  Dutch  elm  {U.  major),  the  smallest  of  the  five,  is  indigenous  to  Holland ;  its  wood 
is  very  inferior.     Elm-trnnks  average  44  ft.  long  and  32  in.  diam.     The  wood  is  very 
durable  when  perfectly  dry  or  constantly  wet.     It  is  not  useful  for  general  buildiuo-  but 
makes  excellent  piles,  and  is  used  in  wet  foundations,  waterworks,  and  pumps ;  also  for 
wheel-naves,  blocks,  keels,  and  gunwales.     It  twists  and  warps  in  drying,  shrinks  con- 
siderably, and  is  difficult  to  work ;  but  is  not  liable  to  split,  and  bears  the  driving  of 
bolts  and  nails  very  well.     Its  weight  is  34-50  lb.  a  cub.  ft. ;  cohesive  force,  C070- 
13,200  lb. ;  strength,  82 ;  stiffness,  78  ;  toughness,  86.     The  colour  of  the  heartwood  is 
a  reddish-brown.     The  sapwood  is  j-ellowish-  or  brownish-white,  with  pores  inclined  to 
red.     The  medullary  rays  are  not  visible.     The  wood  is  porous  and  very  twisted  in 
grain ;  is  very  strong  across  the  grain  ;  bears  driving  nails  very  well ;  is  very  fibrous, 
dense,  and  tough,  and  offers  a  great  resistance  to  crushing.     It  has  a  peculiar  odour,  and 
is  very  durable  if  kept  constantly  under  water  or  constantly  dry,  but  will  not  bear 
alternations  of  wet  and  dry.     Is  subject  to  attacks  of  worms.     None  but  fresh-cut  logs 
should  be  used,  for  after  exposure,  they  become  covered  with  yellow  doaty  spots,  and 
decay  will  be  found  to  have  set  in.     The  wood  warps  very  much  on  account  of  the 
irregularity  of  its  fibre.     For  this  reason  it  should  be  used  in  large  scantling,  or  smaller 
pieces  should  be  cut  just  before  they  are  required ;  for  the  same  reason  it  is  difficult  to 


Carpentry — Woods.  133 

■work.  The  sapwood  •withstands  decay  as  -well  as  the  heart.  Elm  timber  should  bo 
stored  under  water  to  prevent  decay.  Three  species  of  elm  are  indigenous  to  N.  America, 
and  have  similar  uses  to  the  European  kinds:— The  common  American  (6'.  americana) 
grows  in  low  woods  from  New  England  to  Canada,  reaching  SO-100  ft.  high  ;  its 
wood  is  inferior  to  English.  The  Canada  rock  or  mountain  ( L'.  racemosa)  is  common 
to  Canada  and  the  N.  States;  the  wood  is  used  in  boat-building,  liut  is  very  liable  to 
shrink,  and  gets  shaky  by  exposure  to  sun  and  wind  ;  its  weight  is  47-55  lb.  a  cub.  ft. 
The  slippery  (V.fulca)  gives  an  inferior  wood,  though  much  used  for  various  purposes. 
Quebec  elm  is  valued  at  4.-51.  a  load. 

Eucalyptus. — Besides  the  chief  species  which  are  described  separately  under  their 
common  names,  almost  all  have  considerable  value  as  timber  trees  for  building, 
fencing,  and  general  purposes  throughout  Australia. 

Fir  [Silver]  (Picea  peciinata). — This  large  tree  (100  ft.  high,  and  3-5  ft.  diam.)  is  in- 
digenous to  Euroije,  Asia,  and  N.  America,  growing  in  British  plantations.  It  is  said 
to  attain  its  greatest  perfection  in  this  country  at  SO  years.  The  wood  is  of  good 
quality,  and  much  used  on  the  Continent  for  carpentry  and  ship-building.  Floors 
of  it  remain  permanently  level.  It  is  liable  to  attacks  of  the  worm,  and  lasts  longer 
ia  air  than  in  water.     It  weighs  about  25^  lb.  a  cub.  ft. 

Greenheart  or  Bibiri  {Xectandra  Bodice/  [leucanthaj). — This  celebrated  ship-building 
wood  is  a  native  of  British  Guiana,  and  has  been  largely  exported  from  Demerara 
to  English  dockyards.  It  gives  balks  50-GO  ft.  long  without  a  knot,  and  lS-24  in. 
sq.,  of  hard,  fine-grained,  strong,  and  durable  wood.  It  is  reputed  proof  against  sea- 
worms,  and  placed  in  the  first  class  at  Lloyd's;  it  is  very  difficult  to  work,  on 
account  of  its  splitting  with  great  force.  Its  weight  is  58-G5  lb.  a  cub.  ft. ;  crush- 
ing-weight,! 2,000  lb.;  breaking-weight,  1424  lb.  Tlie  section  is  of  fine  grain,  and 
very  full  of  fine  pores.  The  annual  rings  are  rarely  distinct.  The  heartwood  is  dark- 
green  or  chestnut-coloured,  the  centre  portion  being  deep  brownish-purple  or  almost 
black ;  the  sapwood  is  green,  and  often  not  recognizable  from  the  heart.  An  essential 
oil  causes  it  to  burn  freely.  It  comes  into  the  market  roughly  hewn,  much  bark  being 
left  on  the  angles,  and  the  ends  of  the  butts  are  not  cut  off  square. 

Gum  [Blue]  {Eucalyptus  Globulus). — This  Australian  and  Tasmauian  tree  is  of  rapid 
growth,  and  often  reaches  150-300  ft.  high  and  10-20  ft,  diam.  Its  wood  is  hard,  com- 
pact, difficult  to  work,  and  liable  to  split,  warp,  and  slirink  in  seasoning.  It  is  used  for 
general  carpentry  and  wheel-spokes.  Its  weight  is  €0  lb.  a  cub.  ft. ;  crushing-force, 
(J700  lb. ;  breaking-weight,  550-900  lb.  It  is  employed  in  the  erection  of  buildings,  for 
beams,  joists,  &c.,  and  for  railway  sleepers,  piers,  and  bridges.  It  is  also  well  adapted 
for  ship-building  purposes;  from  the  great  length  in  which  it  can  always  be  procured, 
it  is  especially  suitable  for  outside  planking,  and  has  been  used  for  masts  of  vessels, 
but,  owing  to  its  great  weight,  for  the  latter  purpose  has  given  place  to  Kaurie  ;  it  is 
also  bent  and  used  for  street  cab  shafts,  &c. 

Gum  [Red]  (Eucalyptus  rostrata),  of  Australia,  is  a  very  hard  compact  wood,  possess- 
ing a  very  handsome  curly  figure ;  it  is  of  light-red  colour,  and  suitable  for  veneering 
purposes  for  furniture  ;  it  is  largely  used  for  posts,  resembling  jarrah  in  durability.  Pro- 
perly selecteii  and  seasoned,  it  is  well  adapted  for  shiji-building,  culverts,  bridges, 
wharves,  railway  sleepers,  engine  bufiers,  &c. 

Gum  [White  or  Swamj:)]  Eucalyptus  viininah's). — This  tree  is  found  chiefly  in  Tas- 
mania, and  a  variety  called  the  Tuvart  occurs  in  "\V.  Australia.  The  wood  is  valued  for 
its  great  strength,  and  is  sometimes  used  in  ship-building,  but  more  in  house-building, 
and  for  puri^oses  where  weight  is  not  an  objection.  It  is  sound  and  durable,  shrinks 
little,  but  has  a  twisted  grain,  which  makes  it  difficult  to  work.  Its  weight  is  about 
70  lb.  a  cub.  ft. ;  crushing-force,  10,000  lb. ;  breaking-weight,  730  lb. 

Hickory  or  "White  Walnut  (Carya  IJuglans']  alba). — There  are  about  a  dozen  species  of 
hickory,  natives  of  N.  America,  forming  large   forest  trees.     Their  timber  is  coarse- 


13-i  Carpentry — Woods. 

grained,  and  very  strong,  tough,  and  heavy  ;  but  i3  unsuited  for  building,  as  it  does  not 
bear  exposure  to  the  weather,  and  is  much  attacked  by  insects.  It  is  extensively  used 
where  toughness  and  elasticity  are  required,  such  as  for  barrel-hoops,  presses,  handles, 
shafts  and  poles  of  wheel  carriages,  fishing-rods,  and  even  light  furniture.  The  most 
important  is  the  shell-bark,  scaly-bark,  or  shag-bark  (C.  alba),  common  throughout  the 
Alleglianies  from  Carolina  to  New  Hampshire,  growing  80-90  ft.  high  and  2-3  ft.  diam. 
Hickory  [Australian]  (^Acacia  snpporosa)  is  a  valuable  wood  for  many  purposes.  It 
is  exceedingly  tough  and  elastic,  and  would  make  good  gig  shafts,  handles  for  tools, 
gun-stocks,  &c.  Tall  straight  spars,  fit  for  masts,  can  be  obtained  50  to  100  ft.  long 
and  18  in.  in  diam. 

Hinau  (Elxocarpus  dentatu-i). — A  small  tree,  about  50  ft.  high,  and  18  in.  thick  in 
stem.  "Wood,  a  yellowish-brown  colour  and  close  grained,  very  durable  for  fencing  and 
piles.     Common  throughout  Xew  Zealand.     Makes  a  very  handsome  furniture  wood. 

Hinoki  (Jtttinogpora  ohtusa)  enjoys  the  highest  repute  in  Japan  for  building  pur- 
poses. The  tree  grows  with  amazing  rapidity  and  vigour,  and  its  wood  la  used  almost 
exclusively  for  the  structure  and  furniture  of  the  temples,  generally  unvarnished.  It 
gives  a  beautifully  white  even  grain  under  the  plane,  and  withstands  damp  so  well  that 
thin  strips  are  used  for  roofing  and  last  a  hundred  years.  The  wood  is  soft  enough  to 
take  the  impression  of  the  finger  nail. 

Hornbeam  {Carpimis  Betulus). — Notwithstanding  that  the  wood  is  remarkable  for 
its  close  grain,  even  texture,  and  consequent  strength,  it  is  seldom  used  for  structiu-al 
purposes.  To  a  certain  extent  this  is  attributable  to  the  tree  not  usually  growing  to 
a  very  large  size,  and  also  to  the  fact  that  when  it  does  it  is  liable  to  become  shaky. 
Hornbeam  has  of  late  been  much  more  largely  used  in  this  country  than  formerly,  it 
having  been  found  to  be  peculiarly  adapted  for  making  lasts  used  by  bootmakers.  This 
wood  being  sent  to  this  country  in  considerable  quantities  from  France,  led  to  the 
discovery  that  it  was  being  used  almost  exclusively  for  the  above  purpose,  and  that  it 
was  imported  in  sacks,  each  containing  a  number  of  small  blocks,  in  shape  of  the  rough 
outline  of  a  last.  The  advantage  over  other  woods,  and  even  over  beech,  which  has 
hitherto  been  considered  the  beat  wood  for  last-making,  is  that,  after  the  withdrawal  of 
nails,  the  holes  so  made  close  up,  whicli  is  not  the  case  with  most  other  woods.  The 
wood  is  white  and  close,  with  the  medullary  rays  well  marked,  and  no  sapwood.  Under 
vertical  pressure,  the  fibres  double  up  instead  of  breaking.     It  stands  exposure  well, 

Horoeka,  or  l\y  Tree  {Panax  crassifolium). — An  ornamental,  slender,  and  sparingly 
branched  tree.  The  wood  is  close-grained  and  tough.  Common  in  forests  throughout 
New  Zealand. 

Horopito,  Pepper  Tree,  or  Winter's  Bark  (Brimya  axillaris).— A.  small,  slender,  ever- 
green tree,  very  handsome.  Wood  very  ornamental  in  cabinet-work,  making  handsome 
veneers.     Grows  abundantly  in  forests  throughout  New  Zealand. 

Ironbark  {Eucalyptus  resini/era).— This  rugged  tree  is  found  in  most  parts  of  the 
Australian  continent,  frequently  reaching  100-150  ft.  high  and  3-6  ft.  diam.,  the  usual 
market  logs  being  20-40  ft.  long  and  12-18  in.  sq.  Its  wood  is  straight-grained,  very 
dense,  heavy,  strong,  and  durable,  but  very  difficult  to  work.  It  is  liable  to  be  shaky, 
and  can  only  be  employed  with  advantage  in  stout  planks  or  largo  scantlings.  Its 
weight  is  Gl^'lb.  a  cub.  ft. ;  crushing-force,  9921  lb. ;  breaking-weight?  1000  lb.  It  forms 
one  of  the  hardest  and  heaviest  of  the  Australian  woods,  and  is  highly  prized  by  the 
coachmaker  and  wheelwright  for  the  poles  and  shafts  of  carriages  and  the  spokes  of 
wheels.  Its  greasy  nature  also  renders  it  serviceable  for  the  cogs  of  heavy  wheels,  and 
it  is  valued  for  many  purposes  in  ship-building. 

Ironwood  [Cape]  {Olea  unJulata). — This  S.  African  wood,  the  iarribooti  or  Tiooshe  of 
the  natives,  is  very  heavy,  fine-grained,  and  durable,  and  is  used  for  waggon-axles, 
wheel -cogs,  spokes,  telegraph-poles,  railway-sleepers,  and  piles.  This  is  the  '-black'* 
ironwood.     The  "  white"  (Veprls  lanceolata)  is  used  for  similar  purposes. 


Cakpentry — Woods.  135 

Jack,  or  Ceylon  Mahnjnnv  (Arforarpus  intefjrifolia). — This  nseful  tree  is  a  native  of 
the  E.  Archipelago,  and  is  widely  cultivated  in  Ceylon,  S.  India,  and  all  the  warm  parts 
of  Asia,  maiuly  as  a  shade-tree  for  coffee  and  other  crops.  Its  wood  is  in  very  general 
use  locally  for  making  furniture  ;  it  is  durable,  and  can  be  got  in  logs  21  ft.  long  and 
17  in.  diam.     Its  weight  is  42  lb.  a  cub.  ft. ;  breaking-weight,  COO  lb. 

Jack  [Jungle],  or  Anjilli  {Ariocarpus  hirsuta). — This  species  is  remarkable  for  size 
of  stem,  and  is  found  in  Bengal,  Slalabar,  and  Burma.  Its  wood  is  strong  and  close- 
grained,  and  considered  next  in  value  to  teak  for  ship-building.  Its  weight  is  3S— 19  lb. 
a  cub.  ft. ;  cohesive  force,  13,000-15,000  lb. ;  breaking-weight,  740  lb. 

Jaral  (Lagerstriemia  regiiue')  is  a  valuable  timber  tree  of  Assam,  giving  a  light 
salmon-coloured  wood,  with  coarse  uneven  grain,  very  hard  and  durable,  and  not  liable 
to  rot  under  water.  It  is  used  chiefly  in  boat-builJing  and  for  house-posts.  Full-sized 
trees  run  35  ft.  high  and  7-8  ft.  in  girth,  fetching  61.-SI.  each. 

Jarrah,  Australian  Mahogany,  or  Flooded  or  Eed  Gum  (^Eucalyptus  marginata). — • 
This  tree  attains  greatest  perfection  in  W.  Australia,  reaching  200  ft.  high.  Its  wood  is 
hard,  heavy,  close-grained,  and  very  durable  in  salt  and  fresh  water,  if  cut  before  the 
rising  of  the  sap.  It  is  best  grown  on  the  hills.  It  resists  sea- worms  and  white  ants, 
rendering  it  specially  valuable  for  ships,  jetties,  railway-sleepers  and  telegraph-posts, 
but  shrinks  and  warps  considerably,  so  that  it  is  unfit  for  floors  or  joinery.  Logs  may 
be  got  20-40  ft.  long  and  11-24  in.  sq.  Its  weight  is  62i  lb.  a  cub.  ft. ;  crushing-force, 
7000  lb. ;  breaking-weight,  500  lb.  The  chief  objection  raised  against  it  is  that  it  is 
liable  to  "  shakes,"  the  trees  being  frequently  unsound  at  heart.  For  piles  it  should  be 
used  whole  and  unhewn;  there  is  very  little  sapwood,  and  the  outer  portion  of  the 
heartwood  is  by  far  the  harder,  hence  the  desirability  of  keeping  the  anntilar  rings  intact. 

Kaiwhiria  {Hedycarya  dentata). — A  small  evergreen  tree  20-30  ft.  high ;  the  wood  is 
finely  marked  and  suitable  for  veneering.  Grows  in  the  North  and  South  Island  of  Ne^v 
Zealand,  as  far  south  as  Akaroa. 

Kamahi  {Weinmannia  raceniosa'). — Alarge  tree  ;  trunk  2-4  ft.  diam.,  and  50  ft.  high. 
"Wood  close-grained  and  heavy,  but  rather  brittle ;  might  be  used  for  plane-making  and 
other  joiners'  tools,  block-cutting  for  paper  and  calico  printing,  besides  various  kinds  of 
turnery  and  wood-engraving.  Grows  in  the  middle  and  southern  parts  of  the  Xorthem 
Island  and  throughout  the  Southern  Island  of  Xew  Zealand.  It  is  chiefly  employed 
for  making  the  staves  of  barrels. 

Kanyin  {Dipterocarpus  alatus). — This  magnificent  tree  is  found  chiefly  in  Pegu  and 
the  Straits,  reaching  250  ft.  high.  Its  wood  is  hard  and  close-grained,  excellent  for  all 
house-building  purposes,  but  not  durable  in  wet.  Its  weight  is  45  lb.  a  cub.  ft. ; 
breaking-weight,  750  lb.  Another  species  (D.  turhinaius\  found  in  Assam,  Burma,  and 
the  Andamans,  is  similar,  and  much  used  by  the  natives  in  house-building. 

Kauri,  Cowrie,  or  Pitch-tree  (DaTni/jara  auitralis). — This  gigantic  conifer  is  a  native 
of  New  Zealand,  growing  80-140  ft.  high,  with  a  straight  clean  stem  4-8  ft.  diam.  The 
wood  is  close,  even,  fine-grained,  and  free  from  knots.  It  is  chiefly  used  and  weU 
adapted  for  masts  and  spars ;  also  for  joinery,  as  it  stands  and  glues  well,  and  shrinks 
less  than  pine  or  fir.  But  it  buckles  and  expands  very  much  when  cut  into  narrow  strips 
for  inside  motddings.  Its  weight  is  35-40  lb.  a  cub.  ft. :  cohesive  force,  9600-10,960  lb. 
a  sq.  in.  The  timber  is  in  high  repute  for  deck  and  other  planking  of  ships.  It  pos- 
sesses great  dtirability,  logs  which  had  been  btiried  for  many  years  being  found  in  soimd 
cojiditron,  and  used  a's  raUway  sleepers.  In  the  Thames  goldfield  it  supplies  the  mine 
props,  struts,  and  cap  pieces.  It  is  the  chief  timber  exported  from  New  Zealand.  Some 
of  the  largest  and  soundest  sticks  have  richly  mottled  shading,  which  appears  to  be^an 
abnormal  growth,  due  to  the  bark  being  entangled  in  the  ligneous  portion,  causing 
shaded  parts,  broad  and  narrow,  according  as  the  timber  is  cut  relative  to  their  planes  ; 
such  examples  form  a  valuable  furniture  wood.  The  heartwood  is  yellowish-white  fiine 
and  straight  in  grain,  with  a  silky  lustre  on  the  surface. 


136  Cakpentuy — Woods. 

Kohe-kolie  (Dysoxylum  spectahih). — A  large  forest  tree,  40-50  ft.  liigli.  Wood 
tough,  but  splits  freely,  and  is  considered  durable  as  piles  under  sea-water.  Grows  in 
the  North  Island  of  New  Zealand. 

Kohutuhutu  {Fuchsia  excorticata). — A  small  and  ornamental  tree,  10-30  ft.  high ; 
trunk  sometimes  3  ft.  in  diameter.  It  appears  to  furnish' a  durable  timber.  House  blocks 
of  this,  which  have  been  in  use  in  Dunediu  for  more  than  20  years,  arc  still  sound  and 
good.     Grows  throughout  New  Zealand. 

Kohwai  {Sophora  tetrajjtera). — A  small  or  middling-sized  tree.  Wood  red ;  valuable 
for  fencing,  being  highly  durable ;  it  is  also  adapted  for  cabinet-work.  It  is  used  for 
piles  in  bridges,  wharves,  &c.     Abundant  throughout  New  Zealand. 

Larch  [American  Black],  Tamarak,  or  Hackmatack  (Larix  pendula). — This  tree 
ranges  from  Newfoundland  to  Virginia,  reaching  80-100  ft.  high,  and  2-3  ft.  diam.  The 
wood  is  said  to  nearly  equal  that  of  the  Eurojiean  species. 

Larch  [Common  or  European]  (Larix  europxa). — This  species  is  a  native  of  the  Swiss 
and  Italian  Alps,  Germany,  and  Siberia,  but  not  of  the  Pyrenees  nor  of  Spain.  The  Italian 
is  most  esteemed,  and  has  been  considerably  planted  in  England.  The  tree  grows  straight 
and  rapidly  to  100  ft.  high.  The  wood  is  extremely  durable  in  all  situations,  such  as 
posts,  sleepers,  &c.,  and  is  preferable  to  pine,  pinaster,  or  fir  for  wooden  bridges.  But  it 
is  less  buoyant  and  elastic  than  Northern  Pine,  and  boards  of  it  are  more  apt  to  warp. 
It  burns  with  diiBculty,  and  makes  excellent  ship-timber,  masts,  boats,  posts,  rails,  and 
furniture.  It  is  peculiarly  adapted  for  staircases,  doors,  and  shutters.  It  is  more 
ditficult  to  work  than  Northern  Pine,  but  makes  a  good  surface,  and  takes  oil  or  varnish 
better  than  oak.  The  liability  to  warp  is  said  to  be  obviated  by  barking  the  trees  while 
growing  in  spring,  and  cutting  in  the  following  autumn,  or  next  year ;  this  is  also  said 
to  prevent  dry-rot.  The  wood  weighs  34-36  lb.  a  cub.  ft. ;  cohesive  force,  GOOO 
-13,000  lb. ;  strength,  103 :  stiffness,  79 ;  toughness,  134.  The  wood  is  honev-j'ellow 
or  brownish-white  in  colour,  the  hard  part  of  each  ring  being  of  a  redder  tinge,  silky 
lustre.  There  are  two  kinds  in  this  country,  one  yellowish-white,  cross-grained,  and 
knotty  ;  the  other  (grown  generally  on  a  poor  soil  or  in  elevated  positions)  reddish-brown, 
harder,  and  of  a  straighter  grain.  It  is  the  toughest  and  most  lasting  of  all  the  coniferous 
tribe,  very  strong  and  durable,  shrinks  very  much,  straight  and  even  in  grain,  free  from 
large  knots,  very  liable  to  warp,  stands  well  if  thoroughly  dry,  is  harder  to  work  than 
Baltic  fir,  but  the  surface  is  smoother,  when  worked.  Bears  nails  driven  into  it  better 
than  any  of  the  pines.  Used  chiefly  for  posts  and  palings  exi^osed  to  weather,  railway 
sleepers,  flooring,  stairs,  and  other  positions  where  it  will  have  to  withstand  wear. 

Lignum-vitre  {Guaiacum  officinale). — This  tree  grows  chiefly  on  the  south  side  of 
Jamaica,  and  affords  one  of  the  hardest  and  heaviest  woods,  extremely  useful  for  the 
sheaves  and  blocks  of  jDuUeys,  for  which  purpose  it  should  be  cut  with  a  band  of  sap- 
wood  all  round,  to  prevent  splitting.  Its  weight  is  73  lb.  a  cub.  ft.;  crushing-weight, 
9900  lb.  The  approximate  London  market  value  is  4-lOZ.  a  ton.  Lignum-vitre  grows 
on  several  of  the  Bahama  islands,  and  is  generally  exported  to  Eurojje  and  America. 
The  principal  use  made  of  it  in  the  Bahamas  is  for  hinges  and  fastenings  for  houses 
situated  by  the  sea  shore  or  in  the  vicinity  of  salt  ponds  on  the  islands,  where,  from  the 
quick  corrosion  of  iron  hinges,  &c.,  metal  is  seldom  used. 

Locust-tree  {Ilymenma  Cuurharil). — This  tree  is  a  native  of  S.  America,  and  is  found 
also  in  Jamaica.  Its  wood  is  hard  and  tough,  and  useful  for  house-building.  Its  weight 
is  42  lb.  a  cub.  ft. ;  crushing-force,  7500  lb. ;  breaking-weight,  750  lb. 

Jlahogany  {Swietenia  Mahogani). — This  tree  is  indigenous  to  the  W.  Indies  and 
Central  America.  It  is  of  comparatively  rapid  growth,  reaching  maturity  in  about 
200  years,  and  the  trunk  exceeding  40-50  ft.  long  and  6-12  ft.  diam.  The  wood  is  very 
durable  in  the  dry,  and  not  liable  to  worms.  Its  costliness  restricts  its  use  chietly  to 
furniture ;  it  has  been  extensively  employed  in  maclunery  for  cotton-mills.  It  shrinks 
very  little,  warps  and  twists  less  than  any  other  wood,  and  glues  exceedingly  welL^It 


Caepentry — Woods.  137 

is  imported  in  logs:  those  ^rom  Cuba,  Jamaica,  San  Domingo,  known  as  "  Spanish," 
are  about  20-26  in.  sq.  and  10  ft.  long;  those  from  Honduras,  2-4  ft.  sq.  and  1'1-li  ft. 
long.  The  weight  is  'S5-53  lb.  a  cub.  ft. ;  the  cohesive  force  is  75G0  lb.  in  Spanish,  and 
11,475  lb.  in  Honduras;  the  strength,  stiffness,  and  toughness  are  respectively  67,  7v5, 
and  61  in  Spanish,  and  96,  93,  and  99  in  Honduras.  The  tree  attains  its  greatest 
develoi:)ment  and  grows  most  abundantly  between  10°  N.  Lit.  and  the  Troj^ic  of  Cancer, 
flourishing  best  on  the  higher  crests  of  the  hills,  and  preferring  the  lighter  soils.  It 
is  found  in  abundance  along  the  banks  of  tlie  Usumacinta,  and  other  large  rivers 
flowing  into  the  Gulf  of  Mexico,  as  well  as  in  the  larger  islands  of  the  "W.  Indies. 
British  settlements  for  cutting  and  shipping  the  timber  were  established  so  long  ago 
as  1638-40,  and  the  right  to  the  territory  has  been  maintained  by  Great  Britain,  chiefly 
on  account  of  the  importance  of  this  branch  of  industry.  The  cutting  season  usually 
commences  about  August.  It  is  performed  by  gangs  of  men,  numbering  20-50,  under 
direction  of  a  "  captain  "  and  accompanied  by  a  "  huntsman,'*  the  duty  of  the  latter 
being  to  search  out  suitable  trees,  and  guide  the  cutters  to  them.  The  felled  trees  of  a 
season  are  scattered  over  a  very  wide  area.  All  the  larger  ones  are  "  squared  "  before 
being  brought  away  on  wheeled  trucks  along  the  forest  roads  made  for  the  purpose.  By 
March-April,  felling  and  trimming  are  comi^leted ;  the  dry  season  by  that  time  permits 
the  trucks  to  be  wheeled  to  the  river-banks.  A  gang  of  40  men  work  6  trucks,  each 
requiring  7  pair  of  oxen  and  2  drivers.  Arrived  at  the  river,  the  logs,  duly  initialed,  are 
thrown  into  the  stream ;  the  rainy  season  follows  in  May-June,  and  the  rising  current 
carries  them  seawards,  guided  by  men  following  in  canoes.  A  boom  at  the  river-mouth 
stops  the  timber,  and  enables  each  owner  to  identify  his  property.  They  are  then  made 
up  into  rafts,  and  taken  to  the  whaiwes  for  a  final  trimming  before  shipment.  The 
cutters  often  continue  their  ojierations  far  into  the  interior,  and  over  the  borders  into 
Guatemala  and  Yucatan.  Bahama  mahogany  grows  abundantly  on  Andros  Island  and 
others  of  the  Bahama  group.  It  is  not  exceeded  in  durability  by  any  of  the  Bahama 
woods.  It  grows  to  a  large  size,  but  is  generally  cut  of  small  dimensions,  owing  to  the 
want  of  proper  roads  and  other  means  of  conveyance.  It  is  principally  used  for  bed- 
steads, &c.,  and  the  crooked  trees  and  branches  for  ship  timber.  It  is  a  fine,  hard, 
close-grained,  moderately  heavy  wood,  of  a  fine,  rich  colour,  equal  to  that  of  Spanish 
mahogany,  although  probably  too  hard  to  be  well  adapted  for  the  purj^oses  to  which 
the  latter  is  usually  ajjplied.  Honduras  is  best  for  strength  and  stiftuess,  while  Spanish 
is  most  valued  for  ornamental  purposes.  The  Honduras  wood  is  of  a  golden  or  red- 
brown  colour,  of  various  shades  and  degrees  of  brightness,  often  very  much  veined  and 
mottled.  The  grain  is  coarser  than  that  of  Spanish,  and  the  inferior  qualities  often 
contain  many  grey  specks.  This  timber  is  very  durable  when  kept  dry,  but  does  not  stand 
the  weather  well.  It  is  seldom  attacked  by  dry-rot,  contains  a  resinous  oil  whicli 
prevents  the  attacks  of  insects,  and  is  untouched  by  worms.  It  is  strong,  tough,  and 
flexible  when  fresh,  but  becomes  brittle  when  dry.  It  contains  a  very  small  proportion 
of  sap,  and  is  very  free  from  shakes  and  other  defects.  The  wood  requires  great  care 
in  seasoning,  does  not  shrink  or  warp  much,  but  if  the  seasoning  process  is  carried  on 
too  rapidly  it  is  liable  to  split  into  deep  shakes  externally.  It  holds  glue  very  well,  has 
a  soft  silky  grain,  contains  no  acids  injurious  to  metal  fastenings,  and  is  less  combustible 
than  most  timbers.  It  is  generally  of  a  plain  straight  grain  and  uniform  colour,  but 
is  sometimes  of  wavy  grain  or  figured.  Its  market  forms  are  logs  2-4  ft.  sq.  and 
12-14  ft.  in  length.  Sometimes  planks  have  been  obtained  6-7  ft.  wide.  Mahogany 
is  known  in  the  market  as  "  plain,"  "  veiny,"  "  watered,"  "  velvet-cowl,"  "  bird's-eye,"  and 
"festooned,"  according  to  the  appearance  of  the  vein-formations.  Cuba  or  Spanish 
mahogany  is  distinguished  from  Honduras  by  a  white,  chalk-like  substance  which  fills  its 
pores.  The  wood  is  very  sound,  free  from  shakes,  with  a  beautiful  wavy  grain  or  figure, 
and  capable  of  receiving  a  high  polish.  It  is  used  chiefly  for  furniture  and  ornamental 
purposes,  and  for   ship-building.     Mexican  shows    the  cliaracteristics    of   Honduras. 


138  Caepentey — Woods. 

Some  varlctiGS  of  it  are  figured.  It  may  be  obtained  in  very  largo  sizes,  but  the  wood 
is  spongy  in  the  centre,  and  very  liable  to  starsbakes.  It  is  imported  in  balks  15-36 
in.  sq.,  and  18-30  ft.  in  length.  St.  Domingo  and  Nassau  are  hard,  heavy  varieties,  cf 
deep-red  colour,  generally  -well  veined  or  figured,  and  used  for  cabinet-works.  They  are 
imported  in  very  small  logs,  3-10  ft.  long  and  6-12  in.  sq. 

Mahogany  [African]  {Swietenia  senegalensis).  —  This  hard  and  durable  wood  is 
brought  from  Sierra  Leone,  and  is  much  used  for  purposes  requiring  strength,  hardness, 
and  durability.  But  it  is  very  liable  to  premature  decay,  if  the  heart  is  exposed  in 
felling  or  trimming. 

Mahogany  [E.  Indian]. — Two  species  of  Sioietenia  are  indigenous  to  the  E.  Indies : — 
8.  fehrifuga  is  a  very  large  tree  of  the  mountains  of  Central  Hindostan ;  the  wood  is 
less  beautiful  than  true  mahogany,  but  much  harder,  heavier,  and  more  durable,  being 
considered  the  most  lasting  timber  in  India.  S.  cldoroxijlon  is  found  chiefly  in  the 
Circar  mountains,  and  attains  smaller  dimensions  ;  the  wood  more  resembles  box. 

Maire  {Santalum  Cuimincjhamii). — A  small  tree  10-15  ft.  high,  6-8  in.  diam. ;  wood 
hard,  close-grained,  heavy.  Used  by  the  natives  of  New  Zealand  in  the  manufacture 
of  war  implements.     Has  been  used  as  a  substitute  for  box  by  wood-engravers. 

Maire  [Black]  (Olea  GunningTiamii). — Grows  40-50  ft.  high,  3-i  ft.  diam. ;  timber 
close-f  rained,  heavy,  and  very  durable.  Much  of  this  very  valuable  timber  is  at  present 
destroyed  in  clearing  the  land. 

Maire-taw-hake  {Eurjenia  maire). — A  small  tree  about  40  ft.  high ;  trunk  1-2  ft, 
in  diam.;  timber  compact,  heavy,  and  durable.  Used  for  mooring-posts  and  jetty- 
piles  on  the  Waikato,  w^here  it  has  stood  well  for  7  years.  It  is  highly  valued  for  fencing. 
Common  in  swampy  laud  in  the  North  Island  of  New  Zealand. 

Make  {Arisiotelia  racemosa). — A  small  handsome  tree  G-20  ft.  high,  quick  growing. 
"Wood  very  light,  and  white  in  colour,  and  might  be  applied  to  the  same  purposes  as 
the  lime  tree  in  Britain ;  it  makes  good  veneers. 

Mango  {Mangifera  indica). — This  tree  grows  abundantly  in  India,  where  numerous 
varieties  are  cultivated,  as  also  in  Mauritius,  Brazil,  and  in  other  tropical  climates. 
Its  wood  is  generally  coarse  and  open-grained,  but  is  excellent  for  common  doors  and 
door-posts  when  well  seasoned  ;  it  is  light  and  strong,  but  liable  to  snap ;  it  is  durable 
in  the  dry,  but  decays  rapidly  when  exposed  to  weather  or  water,  and  is  much  attacked 
by  worms  and  ants.  Its  weight  is  41  lb.  a  cub.  ft. ;  cohesive  force,  7700  lb. ;  breaking- 
weight,  560  lb. 

Manuka  {Leptosperminn  ericoides). — A  small  tree  10-80  ft.  high,  highly  ornamental, 
more  especially  when  less  than  20  years  old.  The  timber  can  be  had  28-30  ft.  long,  and 
14  in.  diam.  at  the  butt,  and  10  in.  at  the  small  end.  The  wood  is  hard  and  dark 
coloured,  largely  used  at  present  for  fuel  and  fencing,  axe-handles  and  sheaves  of  blocks, 
and  formerly  by  the  natives  for  spears  and  paddles.  The  old  timber,  from  its  dark- 
coloured  markings,  might  be  used  with  advantage  in  cabinet-work,  and  its  great 
diirability  might  recommend  it  for  many  other  purposes.  Highly  valued  in  Otago  for 
jetty  and  wharf  piles,  as  it  resists  the  marine  worm  better  tlian  any  other  timber  found 
in  the  province.  It  is  extensively  used  for  house  piles.  The  lightest  coloxired  wood, 
called  "  white  manuka,"  is  considered  the  toughest,  and  forms  an  excellent  substitute 
for  hornbeam  in  the  cogs  of  large  spur  wheels.  It  is  abundant  in  New  Zealand  as  a 
scrub,  and  is  found  usually  on  the  poorer  soils,  but  is  rare  as  a  tree  in  large  tracts  to  the 
exclusion  of  other  trees. 

Maple  (Acer  saccharinum). — The  sugar-maple  is  liable  to  a  peculiarity  of  growth, 
which  gives  the  wood  a  knotted  structure,  whence  it  is  called  "  bird's-eye  maple."  The 
cause  of  this  structure  has  never  been  satisfactorily  explained.  The  handsome  appear- 
ance thus  given  to  the  wood  is  the  reason  of  its  value  in  furniture)  and  cabinet 
making. 

Mingi-Mingi  or  Yellowwood   (JJUarla  aviceunixfolia). — An  ornamental  shrub  tree, 


Carpentry — Woods.  •  139- 

trunk  2  ft.  diani.     Wood  close-grained,  with  yellow  markings,  which  render  it  desirable 
for  cabinet-work ;  good  for  veneers.     Occurs  in  Suuth  Island  of  New  Zealand, 

Miio  {Podocarpus  ferrufjinea). — This  is  a  New  Zealand  tree,  giving  brownish  wood 
20-30  ft.  long  and  15-30  in.  sq.,  useful  for  internal  carpentry  and  joinery,  and  weighing 
46  lb.  a  cub.  ft.  It  is  known  as  the  " bastard  black  pine " in  Otago,  the  wood  being  less- 
durable  than  tliat  of  the  matai  or  "  true  black  pine " ;  it  is  reddish,  close-grained  and 
brittle,  the  cross  section  showing  the  heartwood  star-shaped  and  irregular.  Tho 
wood  is  generally  thought  to  be  unfitted  for  piles  and  marine  works,  except  where  only 
partially  exposed  to  the  influence  of  sea-water,  when  it  is  reported  durable. 

Monoao  or  Yellow  Pine  {Dacrydium  Colensoi)  is  a  very  ornamental  tree,  20-80  ft.  higli, 
giving  a  light  and  yellow  wood,  which  is  one  of  the  strongest  and  most  durable  in  New 
Zealand.  Posts  of  this  wood  have  stood  several  hundred  years'  use  among  the  Maoris,, 
and  it  is  greatly  valued  for  furniture. 

Mora  {Mora  excelsa). — This  tree  is  a  native  of  British  Guiana  and  Trinidad,  growing 
luxuriantly  on  sand-reefs  and  barren  clays  of  the  coast  regions,  reaching  130-150  ft.  high, 
and  squaring  18-20  in.  Its  wood  is  extremely  tough,  close,  and  cross-grained,  being  one 
of  tho  most  difficult  to  split.  It  is  one  of  the  eight  first-class  woods  at  Lloyd's,  making 
admirable  keels,  timbers,  beams,  and  knees,  and  in  most  respects  superior  to  oak.  Its 
weight  is  57  lb.  a  cub.  ft. ;  crushing-force,  10,000  lb. ;  breaking-weight,  1212  lb.  The 
wood  is  of  a  chostuut-brown  colour,  sometimes  beautifully  figured.  It  is  free  from  dry- 
rot,  but  subject  to  starshake.     Its  market  form  is  logs  18-35  ft.  long  and  18-20  in.  sq. 

Muskwood  (Euryhia  argophylla)  grows  in  densely  scrubby  places  among  the  moun- 
tain ranges  of  Tasmania,  which  makes  it  difficult  to  get  out.  This  timber  never  grows 
very  high  ;  it  has  a  pleasant  fragrance,  is  of  a  beautiful  mottled  colour,  and  well  adapted 
for  veneering,  fancy  articles  of  furniture,  pianofortes,  &c.  Diam.  G-15  in.,  the  butt 
enlarging  towards  the  ground  to  IJ,  and  even  2J  ft. ;  height,  15-30  ft. ;  sp.  grav.,  about 
0  ■  G85.     Abundant  throughout  tlie  island. 

Mutti  {Terminalla  coriacea). — This  is  a  common  tree  of  Central  and  S.  India.  Its 
wood  is  hard,  heavy,  tough,  fibrous,  close-grained,  rather  difficult  to  work,  unafi"ected  by 
white  ants,  and  considered  extremely  durable.  It  is  used  for  beams  and  telegraph  posts. 
Its  weight  is  60  lb.  a  cub.  ft. ;  breaking-weight,  860  lb. 

Nageswar  {3Iesua  f erred)  is  a  valuable  Assam  timber,  harder  and  more  durable  than 
Jaral,  but  not  so  suitable  for  boat-building,  as  it  is  much  heavier,  and  difficult  to  work- 
Grows  till  80  years  old,  when  it  reaches  a  height  of  45  ft.  and  a  diam.  of  6  ft.,  such  trees 
being  worth  SZ. 

Nan-mu  (Persea  Nanmii). — That  portion  of  tho  Chinese  province  of  Yunnan  which 
lies  between  25°  and  26^  N.  lat.  produces  the  famous  nan-mu  tree,  which  is  highly 
esteemed  by  the  Chinese  for  building  and  coffins,  on  account  of  its  durability  and  pleasant 
odour.  It  is  imported  into  Shanghai  in  planks  measuring  8  ft.  long  and  13-14  in.  wide, 
for  which  the  higliest  price  is  200  dol.  (of  4s.  2d)  a  plank. 

Naugiia. — This  tree  is  generally  found  in  the  Pacific  Islands  on  desert  shores,  or  on 
the  brinks  of  lagoons,  where  its  roots  are  bathed  by  the  tide.  Its  wood  has  great  weight, 
intense  hardness,  and  closeness  of  gi'ain.  It  is  considered  a  valuable  substitute  for  box 
for  wood-engraving.     Blocks  18  in.  diam.  are  common. 

Neem  {MeUa  Azadirachtd). — This  is  a  common,  hardy,  and  quick-growing  Indian 
tree,  reaching  40-50  ft.  high,  and  20-24  in.  diam.  The  trunk  and  branches  are  cut 
into  short,  thick  planks,  much  used  for  lintels  of  doors  and  windows.  The  wood  is 
hard  and  durable,  but  attacked  by  insects.  Its  fragrant  odour  makes  it  in  request  by 
natives  for  doors  and  door-frames.  It  is  difficult  to  work,  takes  a  fine  polisli,  and  is 
good  for  joinery  where  strength  is  not  demanded ;  but  becomes  brittle  and  liable  to 
snap  when  dry.  Its  weight  is  51  lb.  a  cub.  ft. ;  cohesive  force  C940  lb. ;  breaking-weight, 
600  lb. 

Nci-nei  {DacrophyJlum  longifulium). — Wood  is  white,  marked  with  satin-like  specks,. 


140  Carpentry — AVoods. 

and  is  adapted  for  oabinet-vrork.  Grows  in  South  Island  of  New  Zealand,  and  in 
Lord  Auckland's  group  and  Campbell's  Island.  The  tree  in  the  vicinity  of  Dunedin 
attains  a  diam.  of  10-12  in. 

Oak   {Quircus  spp.). — The   most  comnaon    British   oak   is    Q.  pedunculata,   found 
throughout  Europe  from  Sweden  to  the  Mediterranean,  and  in  N.  Africa  and  Asia, 
Its  wood  is  tolerably  straight  and  fine  in  the  grain,  and  generally  free  from  knots.     It 
splits  freely,  makes  good  laths  for  plasterers  and  slaters,  and  is  esteemed  the  best  kind 
for  joists,  rafters,  and  other  purposes  where  a  stiff,  straight  wood  is  desirable.     The 
"  durmast"  oak  ((?.  puhescens)  has  the  same  range  as  the  preceding,  but  predominates 
in  the  German  forests.     Its  wood  is  heavier,  harder  and  more  elastic,  liable  to  warp, 
and  difficult  to  split.     Both  are  equally  valuable  in  ship-building.     Quantities  of  Oak 
timber  are  shipped  from  Norway,  Holland,  and  the  Baltic  ports,  but  are  inferior  to 
English-grown  for  sliip-buildiug,  though  useful  for  other  purposes.    A  third  kind  is  the 
cluster-fruited  or  "  bay"  oak  (Q.  sessilijlora).     Of  American  oaks,  the  most  important 
are  as  follows:   The  chestnut-leaved  (Q.  prinos)  gives  a  coarse-grained  wood,  very 
serviceable  for  wheel-carriages.     The  red  {Q.  rubra),  in  Canada  and  the  AUeghanies, 
affords  a  light,  spongy  wood,  useful  for  staves.     Tlie  wood  of  the  white  oak  {Q.  alba), 
ranging  from  Canada  to  Carolina,  is  tough,  pliable,  and  durable,  being  the  best  of  the 
American  kinds,  but  less  durable  than  British.     It  is  exported  from  Canada  to  Europe 
as  "  American  oak."     The  iron  or  post  oak  (Q-  oUmihba),  found  in  the  forests  of  Mary- 
land and  Virginia,  is  frequently  called  the  "  box  white  oak,"  and  chiefly  used  for  posts 
and   fenciug.      The   live   oak  (Q.  virens)    is   the   best  American   &hip-building  kind, 
inhabitiug  the  Virginian  coast.     Oak  warps,  twists,  and  shrinks  much  in  drying.     Its 
weight  is  37-GS  lb.  a  cub.  ft.,  according  to  the  kind  ;  cohesive  force,  7850-17,892  lb.    It 
is  valuable  for  all  situations  where  it  is  exposed  to  the  weather,  and  where  its  warping 
and  flexibility  are  not  objectionable.     Quebec  oak  is  worth  about  il.  10s.-7Z.  a  load ; 
Dantzic  and  Memel,  31.  10s.-5Z.     It  is  generally  considered  that  the  timber  from  the 
stalk-fruited  oak  is  superior  to  that  from  the  bay  oak.     The  resijective  characteristics 
of  the  two  varieties  are : — The  wood  of  the  stalk-fruited  oak  is  lighter  in  colour  than 
the  other.     It  has  a  straight  grain,  is  generally  free  from  knots,  has  numerous  and 
distinct    medullary  rays,  and  good  silver  grain ;  it  is  easy  to  work  and  less  liable  to 
warp,  and  is  better  suited  for  ornamental  work,  joists,  rafters,  and  wherever  stiffness 
and  accuracy  of  form  are  required ;   it  splits  well  and  makes  good  laths.     The  timber 
of  the  cluster-fruited  oak  is  darker   in  colour,    more  flexible,  tougher,  hea%Her,  and 
harder  ;    it   has  but  few   large    medullary  rays,  so  that  in  old  buildings  it  has  been 
mistaken  for  chestnut;  it  is  liable  to  warp,  difficult  to  split,  not   suited  for   laths  or 
ornamental  purposes,  but  is  better  where  flexibility  or  resistance  to  shocks  is  required. 
On  the  whole  they  so  much  resemble  each  other  that  few  are  able  to  sjieak  positiveh' 
as  to  their  identity ;   but  the  Durmast  oak  is  decidedly  of  inferior  quality.     Oak  is 
sometimes  felled  in  the  spring  for  the  sake  of  the  bark   (instead  of  being   stripped 
in  the  spring  and  felled  in  the  winter) ;  the  tree  being   then  full  of  sap,  the  timber 
is  not  durable.     American  oak  has  a  pale  reddish-brown  colour,  with  a  straighter  and 
coarser  grain   than   English.     The   timber  is    sound,  hard,  and  tough,  very  elastic, 
shrinks  very  slightly,  and  is  capable  of  being  bent  to  any  form  when  steamed.     It  is 
not  so  strong  or  durable  as  English  oak,  but  is  superior  to  any  other  foreign  oak  in 
those   respects.     It  may  be  used  for  ship-building,  and  for  many  parts  of  buildings. 
It  is  imjwrted  in  very  large-sized  logs  varying  from  25  to  40  It.  in  length,  and  from 
12  to  28  in.  in  thickness;    also  in   2-4  in.   planks,  and  in   thick  stuff  of  4j-10  in. 
Dantzic  oak  is  grown  chiefly  in  Poland,  and  sliij)ped  also  at  Memel  and  Stettin.     I,t 
is  of  dark-brown  colour,  with  a  close,  straight,  and  compact  grain,  bright  medullary 
rays,  free  from  knots,  very  elastic,  easily  bent  when  steamed,  and  moderately  durable. 
It  is  used  for  planking,  shiii-building,  &c.     It  is  clasi^ified  as  "crown"  and  "crown 
brack "  qualities,  marked  respectively  W  and  WW.     It  is  imported  in  logs   18-30  ft. 


Carpentry — Woods.  141 

Iong,10-1G  in.sq.,  and  in  planks  averaging  32  ft.  long,  0-15  in.  wide,  and  2-S  in.  thick. 
French  oak  closely  resembles  British  in  colour,  quality,  texture,  and  "eneral  characteristics. 
Kiga  oak  is  grown  in  Russia,  and  is  like  that  shipped  from  Dantzic,  but  with  more 
numerous  and  distinct  medullary  rays.  It  is  valued  for  its  silver  "rain,  and  is 
imported  in  logs  of  nearly  semicircular  section.  Italian  (Sardinian)  oak  is  from  several 
varieties  of  the  tree.  It  is  of  a  brown  colour,  hard,  tough,  strong,  subject  to  splits  and 
shakes  in  seasoning,  difficult  to  work,  but  free  from  defects,  and  extensively  used  for 
ship-building  in  her  Majesty's  dockyards.  "Wainscot"  is  a  species  of  oak,  soft  and 
easily  worked,  not  liable  to  warp  or  split,  and  highly  figured  ;  it  is  obtained  by  convert- 
ing the  timber  so  as  to  show  the  silver  grain,  which  makes  the  wood  very  valuable  for 
veneers,  and  other  ornamental  work.  It  is  imported  chiefly  from  Holland  and  Riga,  in 
semicircular  logs.  "  Clap  Boarding "  is  a  description  of  oak  imported  from  Norway, 
inferior  to  wainscot,  and  distinguished  from  it  by  bein;?  full  of  white-coloured  streaks. 

Oak  [African],  African  Teak,  or  Tnrtosa.  (^Olcl field ia  africana).— This  important  W. 
African  timber  has  lately  been  largely  imported  from  Sierra  Leone  as  a  substitute  for 
oak  and  teak.  Though  stronger  than  these,  its  great  weight  precludes  its  general  use  ; 
but  it  is  valuable  for  certain  parts  of  ships,  as  beams,  keelsons,  waterways,  and  it  will 
stand  much  heat  in  the  wake  of  steamer  fires,  decaying  rapidly,  however,  in  confined 
situations.  It  warps  in  planks,  swells  with  wet,  and  splits  in  drying  again ;  it  is  not 
proof  against  insects.  Its  weight  is  5S-G1  lb.  a  cub.  ft. ;  cohodive  force,  17,000- 
21,000  lb. 

Oak  [Australian].— Two  hard-wooded  trees  of  Australia  are  the  forest-oak  (Caswarwia 
torulusa)  and  the  forest  swamp-oak  {C.  j^aJudosn).  They  reach  40-GO  ft.  high  and 
12-30  in.  diam.,  and  are  used  in  house-building,  mainly  for  shingles,  as  they  split 
almost  as  neatly  as  slate.  They  weigh  50  lb.  a  cub.  ft. ;  ^rushing- force,  5500  lb.  ; 
breaking-weight,  700  lb.  The  she-oak  (C.  quadrivalvis)  and  he-oak  (C  suherosa')  of 
Tasmania  are  used  mostly  for  ornamental  purposes.  C.  leptodada  and  C.  cristata 
are  other  species  well  adapted  for  furniture  purposes  from  the  singular  beauty  of  tlieir 
grain.  They  are  used  for  certain  applications  in  boat-building,  but  rarely  found  to  exceed 
2-3  ft.  in  diameter.  The  wood  is  excellent  for  turnery  purposes  and  the  manufacture  of 
ornamental  work. 

Pai-cli'ha  {Euonymus  sp.). — The  wood  of  this  tree  has  been  proposed  as  a  substitute 
for  boxwood,  being  extensively  produced  in  China,  and  largely  used  at  Ningpo  and 
other  places  for  wood-carving.  It  is  very  white,  of  fine  grain,  cuts  easily,  and  is  well 
suited  for  carved  frames,  cabinets,  &c. ;  but  it  is  not  at  all  likely  to  supersede  box-wood, 
though  well  fitted  for  coarser  work. 

Pear  (Pyrus  communis). — Pear-tree  wood  is  one  of  the  heaviest  and  hardest  of  the 
timbers  indigenous  to  Britain.  It  has  a  compact,  fine  grain,  and  takes  a  high  polish  ; 
it  is  in  great  request  by  millwrights  in  France  for  making  cog-wheels,  rollers,  cylinders, 
blocks,  &c.,  and  is  preferred  before  all  others  for  the  screws  of  wine-presses.  It  ranks 
second  to  bos  for  wood-engraving  and  turnery. 

Persimmon  {Diospyros  viniiniana). — The  Virginian  date-palm  or  persimmon  is  a 
native  of  the  United  States,  growing  50-GO  ft.  high  and  IJ  ft.  diam.  Its  heartwood 
is  brown,  hard,  and  elastic,  but  liable  to  split ;  it  has  been  with  some  success  introduced 
into  England  as  a  substitute  for  boxwood  in  shuttle-making  and  wood-engraving. 

Pine  [Black],  or  Matai  (Podocarpns  spicata). — This  New  Zealand  timber  is  much 
more  durable  than  Miro,  and  is  used  for  all  purposes  where  strength  and  solidity  are 
required.  Its  weight  is  40  lb.  a  cub.  ft. ;  breaking-weight,  420-SOO  lb.  It  is  a  largo 
tree,  80  ft.  high  and  with  a  trunk  2-4  ft.  in  diameter.  The  wood  is  yellowish,  close- 
grained,  and  durable ;  among  the  various  purposes  to  which  it  is  applied  may  be 
mentioned  piles  for  bridges,  wharves  and  jetties,  bed-plates  for  machinery,  millwrights' 
work,  flooring,  house  blocks,  railway  sleepers,  fencing,  and  bridges.  It  has  been  kuowa 
to  resist  exposure  for  over  200  years  in  a  damp  situation. 


142  Carpentry — Woods. 

Pine  [Cluster],  or  Pinaster  (Finns  Pinaster). — This  pine  inhabits  the  rocky  mountains 
■of  Europe,  and  is  cultivated  in  English  plantations ;  it  reaches  50-60  and  even  70  ft. 
in  height.  It  likes  deep  dry  sand,  or  sandy  loam  in  a  dry  bottom  ;  but  avoids  all 
calcareous  soils.  The  wood  is  said  to  be  more  durable  in  water  than  in  air.  It  is  much 
used  in  France  for  shipping-packages,  piles  and  props  in  ship-building,  common 
carpentry  and  fuel.     It  weighs  25  J  lb.  a  cub.  ft. 

Pine  [Huon]  {Dacrydium  Franldinii). — This  tree  is  said  to  be  abundant  in  portions 
of  S.W.  Tasmania,  growing  50-100  ft.  high  and  3-S  ft.  diam.  The  wood  is  clean  and 
fine-grained,  being  closer  and  more  durable  than  American  White  Pine,  and  can  be  had 
in  logs  12-20  ft.  long  and  2  ft.  sq.  Its  weight  is  40  lb.  a  cub.  ft.  It  is  considered  one 
■of  the  handsomest  and  most  suitable  woods  for  bedroom  furniture,  bearing  a  strong 
Tesemblance  to  satinwood.  From  its  lasting  qualities,  it  is  much  prized  for  ship- 
building. 

Pine  [Moreton  Bay]  (Araucaria  CimningJmmi). — This  abundant  Queensland  tree 
grows  over  150  ft.  high  and  5  ft.  dium.,  giving  spars  80-100  ft.  long.  Its  wood  is  straight- 
grained,  tough,  and  excellent  for  joinery;  but  is  not  so  durable  as  Yellow  Pine,  and  is 
liable  to  attacks  of  sea-worms  and  white  ants.  It  is  used  for  flooring  and  general 
■carpentry,  and  for  shingles ;  it  holds  nails  and  screws  well.  Its  weight  is  45  lb.  a  cub.  ft. 
It  is  strong  and  lasting  either  when  dry  or  actually  under  water,  but  will  not  bear 
alternations  of  dryness  and  damp.  When  grown  on  the  mountains  of  the  interior,  the 
wood  is  fine-grained  and  takes  a  polish  which  is  described  as  superior  to  that  of  satin- 
wood  or  bird's-eye  maple.     Its  average  value  is  55.s.-70s.  per  1000  ft.  super. 

Pine  [Norfolk  Island]  (Araucaria  excelsa). — This  tree  inhabits  Norfolk  Island  and 
Australia,  growing  200-250  ft.  high  and  10-12  ft.  diam.  Its  wood  is  tough,  close- 
grained,  and  very  durable  for  indoor  work. 

Pine  [Northern],  or  Red,  Yellow,  Scotch,  Memel,  Riga,  or  Dantzic  Fir  (Pinus 
^ylvestris). — This  tree  forms  with  the  spruce  fir  the  great  forests  of  Scandinavia  and 
Russia,  and  attains  considerable  size  in  the  highlands  of  Scotland.  The  logs  shipped 
from  Stettin  reach  18-20  in.  sq. ;  those  from  Dantzic,  14-16  in.  and  even  21  in.  sq. 
and  up  to  40-60  ft.  long;  from  Slemel,  up  to  13  in.  sq.  and  35  ft.  long;  from  Riga, 
12  in.  sq.  and  40  ft.  long,  and  spars  18-25  in.  diam.  and  70-80  ft.  long;  Swedish  and 
Norwegian,  up  to  12  in.  sq.  It  comes  also  in  planks  (11  in.  wide),  deals  (9  in.),  and 
Ijattens  (7  in.).  The  best  arc  Christiana  yellow  deals,  but  contain  much  sap ;  Stockholm 
and  Gefle  are  more  disposed  to  warp ;  Gottenburg  are  strong,  but  bad  for  joinery ; 
Archangel  and  Onega  are  good  for  joinery,  but  not  durable  in  damp ;  Wiborg  are  the 
best  Russian,  but  inclined  to  sap  ;  Petersburg  and  Narva  yellow  are  inferior  to  Arch- 
angel. Well-seasoned  pine  is  almost  as  durable  as  oak.  Its  lightness  and  stiffness 
lender  it  the  best  timber  for  beams,  girders,  joists,  rafters,  and  framing;  it  is  much 
xised  for  masts,  and  for  joinery  is  superior  to  oak  on  all  scores.  The  hardest  comes 
from  the  coldest  districts.  The  cohesive  force  is  7000-14,000  lb.  per  sq.  in. ;  weight, 
29-40  lb.  per  cub.  ft.;  strength,  80;  stiffness,  114;  toughness,  56.  The  colour  of  the 
wood  of  different  varieties  is  not  uniform ;  it  is  generally  reddish-yellow  or  honey-yellow 
of  unequal  depths  of  brightness.  The  section  shows  alternate  hard  and  soft  circles, 
one  part  of  each  annual  ring  being  soft  and  light-coloured,  the  other  harder  and  darker. 
It  has  a  strong  resinous  odour  and  flavour,  and  works  easily  when  not  too  highly 
Te.sinous.  Foreign  wood  shrinks  about  -j'^  in  width  in  seasoning  from  the  log.  In  the 
best  timber  the  annual  rings  do  not  exceed  J^j  in.  in  thickness,  and  the  dark  parts  of 
tlie  rings  are  bright,  reddish,  hard,  and  dry,  neither  leaving  a  woolly  surface  after  the 
saw  nor  choking  the  teeth  with  rosin.  Inferior  kinds  have  thick  rings,  and  their  dark 
portion  is  either  more  yellow,  heavier,  and  more  resinous,  or  is  spongj-,  less  resinous, 
and  leaves  a  woolly  surface  after  sawing  ;  such  is  neither  strong  nor  durable.  Shavings 
from  good  timber  will  bear  curling  2  or  3  times  round  the  finger,  those  from  bad  will 
break  off.     The  best  balks  come  from  Dantzic.  Memel,  and  Riga.     Dantzic  is  strong, 


Carpentry — Wood?.  143 

toiigli,  clastic,  easily  worked,  and  durable  when  seasoned.  It  contains  (especially  in 
small  trees)  much  sapwood,  and  large  and  dead  knots,  while  the  heart  is  often  loose  and 
cuppy.  The  balks  run  18-45  ft.  long  and  14-16  in.  sq.  ;  deals,  18-50  ft.  long  and 
2-5  in.  thick.  Memel  is  similar  to  Dantzic,  but  hardly  so  stron;;,  and  only  13-14  in.  sn. 
Eiga  is  somewhat  weaker  than  Dantzic,  but  remarkable  for  straightiiess,  paucity  of 
sapwood,  and  absence  of  knots ;  being  often  rather  shaky  at  the  centre,  it  is  not  so  "-ood 
for  turning  into  deals.  Norway  is  small,  tough,  and  durable,  but  generally  contains 
much  sapwood.  The  balks  are  only  8-9  in.  sq.  Swedish  resembles  Prussian,  but  the 
balks  are  generally  tapering,  small,  of  yellowish-white  colour,  soft,  clean,  straight  in 
grain,  with  small  knots  and  very  little  sap,  but  generally  shaky  at  heart,  and  unfit  foi- 
conversion  into  deals.  It  is  cheap,  suitable  for  the  coarser  purposes  of  carpentry,  and 
used  chiefly  for  scaffolding.  Balks  are  generally  20-35  ft.  long,  and  10-12  in.  sq. 
Planks,  deals,  and  battens  from  the  Baltic,  cut  from  northern  pine,  are  known  as 
"yellow"  or  "red"  deal;  when  cut  from  spruce,  they  are  called  "white"  deals. 
Taking  deals,  battens,  &c.,  in  a  general  way,  the  order  of  quality  would  stand  first  or 
best  with  Prussia;  then  with  Russia,  Sweden,  and  Finland;  and  lastly  witli  Norway. 
Prussian  (Memel,  Dantzic,  Stettin)  deals  are  very  durable  and  adapted  for  external 
■work,  but  are  chiefly  used  for  ship-building,  being  2-4  in.  thick.  The  timber  from  the 
southern  ports,  being  coarse  and  wide  in  the  grain,  cannot  compete  in  the  converted 
form  as  deals,  &c.,  with  the  closer-grained  and  cleaner  exports  from  the  more  northern 
ports.  Russian  (Petersburg,  Onega,  Archangel,  Narva)  are  the  best  deals  imported  for 
building  purposes.  They  are  very  free  from  sap,  knots,  shakes,  or  other  imperfections ; 
of  a  clean  grain,  and  hard,  well-wearing  surface,  which  makes  them  well  adapted  for 
flooring,  joinery,  &c.  The  lower  qualities  are  of  course  subject  to  defects.  Petersburg 
deals  are  apt  to  be  shaky,  having  a  great  many  centres  in  the  planks  and  deals,  but  tlie 
best  qualities  are  very  clean  and  free  from  knots.  They  are  very  subject  to  dry  rot. 
All  Russian  deals  are  unfit  for  work  exposed  to  damp.  In  those  from  Archangel  and 
Onega  the  knots  are  often  surrounded  by  dead  bark,  and  drop  out  when  the  timber  is 
worked.  Wyborg  deals  are  sometimes  of  very  good  quality,  but  often  full  of  sap. 
Finland  and  Nyland  deals  are  14  ft.  long,  very  durable,  but  fit  only  for  the  carpenter. 
Norwegian  (Christiania,  Dram)  yellow  deals  and  battens  used  to  bear  a  high  character, 
being  clean  and  carefully  converted,  but  are  now  very  scarce.  Bluch  of  the  Norwegian 
timber  is  imported  in  the  shape  of  prepared  flooring  and  matched  boarding.  Dram 
fattens  often  suffer  from  dry  rot,  especially  when  badly  stacked.  Of  Swedish  (Gefle, 
Stockholm,  Holmsund,  Soderham,  Gottenburg,  Hernosaud,  Sundswall)  the  greater 
portion  is  coarse  and  bad,  but  some  of  the  very  best  Baltic  deal,  both  yellow  and  white, 
comes  from  Gefle  and  Soderham.  The  best  Swedish  run  more  sound  and  even  in 
quality  than  Russian,  from  the  diflerent  way  in  which  the  timber  is  converted.  A  balk 
of  Russian  timber  is  all  cut  into  deals  of  one  quality,  hence  the  numerous  hearts  or 
centres  seen  amongst  them,  which  are  so  liable  to  shake  and  split ;  whereas  in  Swedish 
timber  the  inner  and  the  outer  wood  are  converted  into  different  qualities  of  deals. 
Hence  the  value  of  first-class  Swedish  goods.  4-in.  deals  should  never  be  used  for 
cutting  into  boards,  as  they  are  cut  from  the  centres  of  the  logs.  3- in.  deals,  the  general 
thickness  of  Russian  goods,  are  open  to  the  same  objection.  Swedish  2J-  and  2-iu.  of 
good  quality  are  to  be  preferred  to  3-in.,  since  they  are  all  cut  from  the  sound  outer 
wood.  Swedish  deals  are  fit  for  ordinary  carcase  work,  but,  from  their  liability  to  warp, 
cannot  be  depended  upon  for  joiners'  work.  They  are  commonly  used  for  all  purposes 
connected  with  building,  especially  for  floors. 

Pine  [Pitch]  (Pmua  rigida  [res/nosft]).— This  species  is  found  throughout  Canada 
and  the  United  States,  most  abundantly  along  the  Atlantic  coast.  The  wood  is  heavy, 
close-grained,  elastic,  and  durable,  but  very  brittle  when  old  or  dry,  and  difficult  to 
plane.  The  heartwood  is  good  against  alternate  dump  and  dryness,  but  inferior  to 
White  Pine  underground.    Its  weight  is  41  lb.  per  cub.  ft. ;  cohesive  force,  979G  lb.  per 


144  Carpentry — Woods. 

sq.  in. ;  stiffness,  73  ;  strength,  S2  ;  toughness,  92.  The  best  comes  from  the  S.  States  of 
N.  America,  chiefly  from  the  ports  of  Savaunali,  Ilarien,  and  Pensacola.  Tlie  colour  is 
reildish-white  or  brown ;  the  annual  rings  are  wide,  strongly  marked,  and  form  beautiful 
figures  after  working  and  varnishing.  The  timber  is  very  resinous,  making  it  sticky  and 
troublesome  to  plane,  but  very  durable  ;  it  is  hard,  heavy,  very  strong,  free  from  knots, 
but  contains  much  sap  wood,  is  subject  to  heart  and  cup  shake,  and  soon  rots  in  damp  ; 
it  is  brittle  when  dry,  and  often  rendered  inferior  by  the  trees  having  been  tapped  for 
turjientine.  Its  resinous  nature  prevents  its  taking  paint  well.  It  is  used  in  the 
heaviest  timber  structures,  for  deep  planks  in  ships,  aud  makes  very  durable  flooring. 
Market  forms  are  logs  11-18  (aver.  IG)  in.  sq.,  20-45  ft.  long;  planks  20-45  ft.  long, 
10-15  in.  wide,  3-5  in.  thick. 

Pine  [Red,  Norway,  or  Yellow]  (Pinus  riihra  [_resinosaJ). — This  tree  grows  on  dry, 
stony  soils  in  Canada,  Nova  Scotia,  and  the  N.  United  States,  reaching  60-70  ft.  high, 
and  15-25  ft.  diam.  at  5  ft.  above  ground.  The  wood  weighs  37  lb.  per  cub.  ft. ;  it  is 
much  esteemed  in  Canada  for  strength  and  durability,  and,  though  inferior  iu  these 
respects  to  Northern  Pine,  is  preferred  by  English  shipwrights  for  planks  and  spars, 
being  soft,  pliant,  and  easily  worked.  This  timber  has  a  reddish-white  appearance, 
with  clean,  fine  grain,  much  like  Memel,  but  with  larger  knots.  It  is  small,  very  solid 
in  the  centre,  with  li'.tle  sap  or  pith,  tough,  elastic,  not  warping  nor  splitting, 
moderately  strong,  very  durable  where  well  ventilated,  glues  well,  and  suffers  little  loss 
in  conversion.  Cabinet-makers  use  it  for  veneering,  and  sometimes  it  is  employed  for 
internal  house-fittings.  Market  forms  are  logs  16-50  ft.  long,  10-18  in.  sq.,  40  cub  ^^ 
in  contents,  sized  as  "  large,"  "  mixed,"  and  "  building." 

Pine  [Red]  or  Rimu  {Dacrydium  cupressinum). — This  New  Zealand  wood  runs  45  it, 
long,  and  up  to  30  in.  sq.,  and  is  much  used  in  house-framing  and  carpentry,  but  is  not 
so  well  adapted  to  joinery,  as  it  shrinks  irregularly.  It  weighs  40  lb.  a  cub.  ft.  It  is 
an  ornamental  and  useful  wood,  of  red  colour,  clear-grained,  and  solid  ;  it  is  much  used 
for  joisting,  planking,  and  general  building  purposes  from  Wellington  southwards.  Its 
cliief  drawback  is  liability  to  decay  under  the  influence  of  wet.  It  is  largely  employed 
in  the  manufacture  of  furniture,  the  old  wood  being  handsomely  marked  like  rosewood, 
but  of  a  lighter  brown  hue.     The  best  quality  comes  from  the  South  Island. 

Pine   [Weymouth   or   White]  {Finns  strohus). — This    tree   inhabits  the   American 
continent  between  43°  and  47°  N.  lat.,  occupying  almost  all  soils.     The  timber  is  ex- 
ported in  logs  over  3  ft.  sq.  and  30  ft.  long ;  it  makes  excellent  masts ;  is  light,  soft,  free 
from  knots,  easily  worked,  glues  well,  and  is  very  durable  in  dry  climates ;  but  is  unfit  for 
large  timbers,  liable  to  dry-rot,  and  not  durable  in  damp  places,  nor  docs  it  hold  nails 
well.    It  is  largely  employed  for  wooden  houses  aud  timber  bridges  in  America.    Its 
weight  is  28f  lb.  per  cub.  ft.;  cohesive  force,  11,835  lb.;  stiffness,  95;  strength,  99; 
toughness,  103.     The  wood,  when  freshly  cut,  is  of  a  white  or  pale  straw  colour,  but 
becomes  brownish-yellow  when  seasoned ;  the  annual  rings  are  not  very  distinct ;  the 
grain  is  clean  and  straight ;  the  wood  is  very  light  and  soft,  when  planed  has  a  silky 
surface,  and  is  easily  recognized  by  the  short  detached  dark  thin  streaks,  like  short  hair- 
lines, always  running  in  the  direction  of  the  grain.     The  timber  is  as  a  rule  clean,  free 
from  knots,  and  easily  worked,  though  the  top  ends  of  logs  are  sometimes  coarse  and 
knotty  ;  it  is  also  subject  to  cup  and  heart  shakes,  and  the  older  trees  to  sponginess  in 
the  centre.     It  is  much  used  in  America  for  carpenters'  work  of  all  kinds ;  also  for  the 
same  purpose  in  Scotland,  and  iu  some  English  towns,  but  considered  inferior  in  strength 
to  Baltic  timber.     Tlie  great  length  of  the  logs  and  their  freedom  from  defects  causes 
them  to  be  extensively  used  for  masts  and  yards  whose  dimensions  cannot  be  procured 
from  Baltic  timber.     For  joinery  this  wood  is  invaluable,  being  wrought  easily  and 
smoothly  into  mouldings  and  ornamental  work  of  every  description.     It  is  particularly 
adapted  for  panels,  on  account  of  the  great  width  in  which  it  may  be  procured  ;  it  is 
also  much  used  for  making  patterns  for  castings.    Of  market  forms  the  best  are  inch 


Cakpentky — Woods.  145 

masts  rouglil}'  licwn  to  an  octagonal  form.  Next  come  logs  liown  square,  IS-CO  ft. 
long,  averaging  l(j  in.  sq.,  and  containing  G5  cub.  ft.  iu  each  log.  A  few  pieces  are  only 
14  in.  sq. ;  shoit  logs  may  bo  liad  exceeding  even  2G  in.  sq.  Some  3-in.  deals  vary  in  width 
from  9  to  2'1  and  even  32  in.  The  best  are  shipijcd  ut  Quebec.  Goods  from  southera 
iwrts,  such  as  liichibucto,  Miramichi,  Shednc,  are  inferior.  American  yellow  deals  aro 
divided  into  3  principal  classes — Brights,  Dry  floated,  Floated.  Each  of  these  is  divided 
into  3  qualities,  according  to  freedom  from  sa}*,  knots,  &c. ;  the  first  qualily  should 
be  free  from  defects.  First  quality  brights  head  the  classification,  then  first  quality 
dry  floated,  next  first  quality  floated ;  then  come  second  quality  brights,  second  quality 
dry  floated,  and  so  on.  Brights  consist  of  deals  sawn  from  picked  logs  and  shipped 
straight  from  the  sawmills.  Floated  deals  are  floated  in  rafts  down  the  rivers  from  the 
felling  grounds  to  the  shipping  ports.  Dry  floated  deals  are  those  which,  after  floating 
down,  have  been  stacked  and  dried  before  shipment.  Floating  deals  damages  them 
considerably,  besides  discolouring  them.  The  soft  and  absorbent  nature  of  the  wood 
causes  them  to  warp  and  shake  very  much  in  drying,  so  that  floated  deals  should  never 
be  used  for  fine  work. 

Pine  [White]  or  Kahikatea  {Podocarpus  dacrijdioides). — This  New  Zealand  timber 
tree  gives  wood  iO  ft.  long  and  24—10  iu.  sq.,  straight-grained,  soft,  flexible,  warjnng  and 
shrinking  little,  and  well  adapted  for  flooring  and  general  joinery,  though  decaying 
rapidly  iu  damp.  Its  weight  is  30  lb.  a  cub.  ft. ;  breaking-weight,  020  lb.  When 
grown  on  dry  soil,  it  is  good  for  the  jjlaidcs  of  small  boats  ;  but  when  from  swamps,  it  is 
almost  useless.  A  variety  called  "  yellow  pine "  is  largely  sawn  in  Nelson,  and  con- 
sidered to  be  a  durable  building  timber. 

Pine  [Yellow,  Spruce,  or  Short-leaved]  (^riiius  variabilis  and  P.  mitis). — The  former 
species  is  found  from  New  England  to  Georgia,  the  wood  being  much  used  for  all  carpentry, 
and  esteemed  for  large  masts  and  yards  ;  it  is  shipped  to  England  from  Quebec. 
The  latter  is  abundant  in  the  Middle  States  and  throughout  N.  America,  reaching 
50-GO  ft.  high  and  18  in.  diam.  It  is  much  used  locally  for  framework:  the  heartwood 
is  strong  and  durable;  the  sapwood  is  very  inferior. 

Tlnuo  (^riatanus  orient  alis  and  P.  occidental  is). — The  first  species  inhabits  the  Levant 
and  adjoining  countries,  growing  GO-SO  ft.  high  and  up  to  8  ft.  diam.  The  wood  is  more 
figured  than  beech,  and  is  used  in  England  for  furniture ;  in  Persia  it  is  applied  to 
carpentry  in  general.  The  second  species,  sometimes  called  "water-beech,"  "button- 
wood,"  and  "  sycamore,"  is  one  of  the  largest  N.  American  trees,  reaching  12  ft.  diam. 
on  the  Ohio  and  Mississippi,  but  generally  3-4  ft.  The  wood  is  harder  than  the  oriental 
kind,  handsome  when  cut,  works  easily,  and  stands  fairly  well,  but  is  short-grained  and 
easily  broken.  It  is  very  durable  in  water,  and  preferred  in  America  for  quays.  lis 
weight  is  40-4G  lb.  a  cub  ft.;  cohesive  force,  11,000  lb.;  strength,  92;  stifi'ness,  78; 
toughness,  108. 

Pohutukawa  (Metrosideros  tomentosa). — This  tree  has  numerous  massive  arms ;  its 
height  is  30-60  ft. ;  trunk  2-4  ft.  in  diam.  Tlie  timber  is  specially  adapted  for  the 
purposes  of  the  ship-builder,  and  has  usually  formed  the  framework  of  the  numerous 
vessels  built  in  the  northern  provinces  of  New  Zealand.  Grows  on  rocky  coasts,  and  is 
almost  confined  to  the  province  of  Auckland. 

Poon  (Calophijllum  Burmanni). — This  tree  is  abundant  in  Burma,  S.  India,  and  the 
E.  Archipelago.  It  is  tall  and  straight,  and  about  G  ft.  circ.  It  is  used  for  the  decks, 
masts,  and  yards  of  ships,  being  strong  and  light.  Its  texture  is  coarse  and  porous,  but 
unifurm:  it  is  easy  to  saw  and  work  up,  holds  nails  well,  but  is  not  durable  in  damp. 
Its  weight  is  40-55  lb.  a  cub.  ft.  ;  cohesive  force,  8000-14,700  lb.  Another  species 
(C  angustifoliurn)  from  the  Jlalabar  Hills  is  said  to  furnish  spars. 

Poplar  (Popidiis  spp.). — Five  species  of  poplar  are  common  in  England  :  the  white 
(P.  alba),  the  black  (P.  nigra),  the  grey  (P.  canescens),  the  aspen  or  trembling  poplar 
(P.  tremula),  and  the  Lombardy  (P.   dilatata);  and  two  in  America:  the   Ontario 


1-lG  Caepentry — Woods. 

(P.  macrophylla)  and  the  black  Italian  (P.  acladesca).  They  grow  rapidly,  and  Iheir 
Avood  is  generally  soft  and  light,  proving  durable  in  the  dry,  and  not  liahle  to  swell  or 
shrink.  It  makes  good  flooring  for  places  subject  to  little  wear,  and  is  slow  to  burn. 
It  is  much  used  for  butchers'  trays  and  other  purposes  where  weight  is  objectionable. 
T!ie  Lombardy  is  the  lightest  and  least  esteemed,  but  is  proof  against  mice  and  insects. 
The  weight  is  24-33  lb.  a  cub.  ft. ;  cohesive  force,  459G-66il  lb. ;  strength,  50-SG  ; 
fctiflhess,  4-1-G6  ;  toughness,  57-112.  Poplar  is  one  of  the  best  woods  for  paper-making. 
The  colour  of  the  wood  is  yellowish-  or  browish-white.  The  annual  rings  are  a  little 
darker  on  one  side  than  the  other,  and  therefore  distinct.  They  are  of  uniform  texture,  and 
without  large  medullary  rays.  Tlie  wood  is  light  and  soft,  easily  worked  and  carved,, 
only  indented,  not  splintered,  by  a  blow.  It  should  be  well  seasoned  for  2  years  before 
use.     When  kejot  dry,  it  is  tolerably  durable,  and  not  liable  to  swell  or  shrink. 

Pukatea  (^Laiirelia  Novx-Zelandiw). — Height,  130  ft.,  with  buttressed  trunk  3-7  ft. 
in  diam. ;  the  buttresses  15  ft.  thick  at  the  base  ;  wood  soft  and  yellowish,  used  for  small 
boat  planks.  A  variety  of  this  tree  has  dark-coloured  wood  that  is  very  lasting  in 
water,  and  greatly  prized  by  the  natives  in  making  canoes.  Grows  in  the  North  Island 
and  northern  parts  of  the  Middle  Island  of  New  Zealand. 

Puriri  or  Ironwood  (Vitex  littornlis). — A  large  tree,  50-60  ft.  high,  trunk  20  ft.  in 
girth.  Wood  hard,  dark  olive  brown,  much  used  ;  said  to  be  indestructible  under  all 
conditions.  Grows  in  the  northern  parts  of  the  North  Island  of  New  Zealand  only.  It 
is  largely  used  in  the  construction  of  railway  waggons,  and  is  said  to  make  excellent 
furniture,  though  but  little  employed  in  that  direction.  It  splits  freely  and  works 
easily,  and  is  used  wherever  durability  is  essential,  as  in  cart  work,  bridges,  teeth  of 
wheels,  and  fencing-posts. 

Pymma  (Larjerstrxinia  rcrjinx). — The  wood  ofthis abundant.  Indian  tree,  particularly 
in  S.  India,  Burma,  and  Assam,  is  used  more  than  any  except  teak,  especially  in  boat- 
building, and  posts,  beams  and  planks  in  house-building.  Its  weight  is  40  lb.  a  cub.  ft. ; 
cohesive  force,  13,000-15,000  lb. ;  breaking-weight,  C40  lb. 

Pynkado  or  Ironwood  (higa  xylocarpd). — This  valuable  timber  tree  is  found  through- 
out S.  India  and  Burma.  Its  wood  is  hard,  close-grained,  and  durable  ;  but  it  is  heavy, 
not  easily  worked,  and  hard  to  drive  nails  into.  It  is  much  used  in  bridge-building, 
l^osts,  piles,  and  sleepers.  Its  weight  is  58  lb.  a  cub.  ft. ;  cohesive  force,  16,000  lb. ; 
breaking-weight,  800  lb.     Called  also  erool. 

Rata  (Metrosideros  lucida). — Tliis  tree  is  indigenous  to  New  Zealand,  giving  a  hard 
timber  20-25  ft.  long  and  12-30  in.  sq.,  very  dense  and  solid,  weighing  65  lb.  a  cub.  ft. 
A  valuable  cabinet  wood ;  it  is  of  a  dark-red  colour  ;  splits  freely.  It  has  been  much 
used  for  knees  and  timbers  in  ship-building,  and  would  probably  answer  well  for  cogs 
of  spur  wheels.  Grows  rarely  in  the  Norfh  Island,  but  is  abirndant  in  the  South  Island, 
especially  on  the  west  coast.  In  Taranaki  it  is  principally  used  by  mill-  and  wheel- 
wrights. M.  rohusta  grows  50-CO  ft.  high,  diameter  of  trunk  4  ft.,  but  the  descending 
roots  often  form  a  hollow  stem  12  ft.  in  diam.  Timber  closely  resembles  the  last-named 
species,  and  is  equally  dense  and  durable,  while  it  can  be  obtained  of  much  larger  dimen- 
sions. It  is  used  for  ship-building,  but  for  this  purpose  is  inferior  to  the  pohutukawa. 
On  the  tramways  of  the  Thames  it  has  been  used  for  sleepers,  which  are  perfectly  sound 
after  5  years'  use.  Grows  in  the  North  Island  ;  usually  found  in  hilly  situations  from 
Cape  Colville  southwards. 

Eewarewa  {Knigldia  exceha). — A  lofty,  slender  tree  100  ft.  high.  Wood  handsome, 
mottled  red  and  brown,  used  for  furniture  and  shingles,  and  for  fencing,  as  it  splits 
easily.  It  is  a  most  valuable  veneering  wood.  Common  in  the  forests  of  the  Nortlteru 
Island  of  New  Zealand,  growing  upon  the  hills  in  both  rich  and  poor  soils. 

Piohun  {Soymida  fehnfuga). — This  large  forest  tree  of  Central  and  S.  India  affords 
a  close-grained,  strong  and  durable  wood,  which  stands  well  when  underground  or  buried 
in  masonry,  but  not  so  well  when  exposed  to  weather.    It  is  useful  for  palisades,  sleepers, 


Carpentry — Woods.  147 

and  house-work,  and  is  not  very  diiScult  to  work.     Its  weight  is  6G  lb.  a  cub.  ft. ; 
cohesive  force,  15,000  lb.;  breaking-weight,  1000  lb. 

Eoscwood. — Tlie  terra  "rosewood  "  is  apjilied  to  tlio  timber  of  a  numlier  of  trees,  but 
the  most  important  is  the  Brazilian.  Tliis  is  derived  mainly,  it  would  seem,  from 
Dalhergia  nigra,  though  it  appears  equally  probable  that  several  spcci(>,s  of  Trijitolemxa 
and  Maclixrtum  contribute  to  tlie  inferior  grades  imported  thence.  The  wood  is  valued 
for  cabinet-making  purposes.  The  approximate  London  market  values  are  12-25?.  a 
ton  for  Eio,  and  10-22Z.  for  Bahia. 

Sabicu  {Lysiloina  Sahicu). — This  tree  is  indigenous  to  Cuba,  and  found  growing  in 
the  Bahamas,  where  it  has  probably  been  introduced.  Its  wood  is  exceedingly  hard  and 
durable,  and  has  been  much  valued  for  ship-building.  It  has  been  imported  from  the 
Bahamas  iu  uncertain  quantities  for  the  manufacture  of  shuttles  and  bobbins  for  cotton- 
mills.  It  resembles  mahogany  in  appearance,  but  is  darker,  and  generally  well  figured. 
The  wood  is  very  heavy,  weathers  admirably,  and  is  very  free  from  sap  and  shakes. 
The  fibres  are  often  broken  during  the  early  stages  of  the  tree's  existence,  and  the  defect 
is  not  discovered  until  the  timber  is  converted,  so  that  it  is  seldom  used  for  weight-carry- 
ing beams. 

Sal  or  Saul  (Shorea  rohusta). — This  noble  tree  is  found  chiefly  along  the  foot  of  the 
Himalayas,  and  ou  the  Yindhyan  Hills  near  Gaya,  the  best  being  obtained  from  Morung. 
Its  wood  is  strong,  durable,  and  coarse-grained,  with  particularly  straight  and  even 
fibre;  it  dries  very  slowly,  continuing  to  shrink  years  after  other  woods  are  dry.  It  is 
used  chiefly  for  floor-beams,  planks,  and  roof-trusses,  and  can  be  had  in  lengths  of 
30-40  ft.,  and  12-24  in.  sq.  Its  weight  is  55-Gl  lb.  a  cub.  ft. ;  cohesive  force,  11,500  lb. ; 
crushing-force,  8500  lb. ;  breaking-weight,  881  lb. 

Satinwood. — The  satinwood  of  the  Bahamas  is  supposed  to  be  the  timber  of  Maha 
guianensis,  an  almost  unknown  tree.  The  Indian  kind  is  derived  from  Chloroxylon 
Sivietenia,  a  native  of  Ceylon,  the  Coromandel  coast,  and  other  parts  of  India.  The 
former  comes  in  square  logs  or  planks  9-20  in.  wide ;  the  latter,  in  circular  logs  9-30  in. 
diam.  The  chief  use  of  satinwood  is  for  making  the  backs  of  hair-  and  clothes-brushes, 
turnery,  and  veneering.  The  aj^proximate  value  of  San  Domingan  is  6-18c7.  a  ft.  Bahama 
satinwood,  also  called  yellow-wood,  grows  abundantly  on  Andros  Island  and  others  of 
the  Bahamian  group,  and  to  a  large  size.  It  is  a  fine,  hard,  close-grained  wood,  showing 
on  its  polished  surface  a  beautifully  rippled  pattern. 

Sawara  (Eetinospora  ^issi'/era)  is  used  in  Japan  for  the  same  purposes  as  hinoki,  when 
that  is  unprocurable. 

She-pine  (Podocarpus  elata)  is  very  common  in  Queensland,  attaining  80  ft.  in 
height  and  36  in.  in  diam. ;  the  timber  is  free  from  knots,  soft,  close-grained,  and  easily 
worked.     It  is  used  for  joinery  and  spars,  and  worth  G5s.-70s.  per  1000  ft.  super. 

Sissu  or  Seesura  (DaZ^^ergfia  iStss?*)-  — This  tree  is  met  with  in  many  parts  of  India, 
being  said  to  attain  its  greatest  size  at  Chanda.  Its  wood  resembles  the  finest  teak, 
but  is  tougher  and  more  eListic.  Being  usually  crooked,  it  is  unsuited  for  beams,  though 
mucli  used  by  Bengal  ship-builders,  and  in  India  generally  for  joinery  and  furnitui'e. 
Its  weight  is  46^  lb.  a  cub.  ft. ;  cohesive  force,  12,000  lb.  ;  breaking-weight,  700  lb. 

Sneezcwood  or  Nies  Hout  {Pteroxylon  utile). — This  most  durable  S.  African  timber, 
the  oomtata  of  the  natives,  is  invaluable  for  railway-sleepers  and  piles,  being  almost 
imperishable. 

Spruce  [American  "SVliite],  Epinette,  or  Sapinetto  blanche  (Abies  alba). — This  white- 
barked  fir  is  a  native  of  high  mountainous  tracts  in  the  colder  parts  of  N.  America, 
where  it  grows  40-50  ft.  high.  The  wood  is  tougher,  lighter,  less  durable,  and  more 
liable  to  twist  in  drying  than  white  deal,  but  is  occasionally  imported  in  planks  and 
deals.  It  weighs  29  lb.  a  cub.  ft.;  cohesive  force,  8000-10,000  lb.;  strength,  86; 
stiffness,  72  ;  toughness,  102. 

Spruce  [American  Black]  (Abies  nigra). — This  tree  inhabits  Canada  and  the  N. 

L  2 


148  Carpentry — Woods. 

states,  being  most  abundant  in  cold-bottomed  lands  in  Lower  Canada.  It  reaches 
60-70  and  even  100  ft.  high,  but  seldom  exceeds  24:  in.  diam.  The  wood  is  much  used 
in  America  for  ships'  knees,  when  oak  and  larch  are  not  obtainable. 

Spruce  [Red],  or  Newfoundland  Eed  Pine  {Ahies  ruhra).— This  species  grows  in 
Nova  Scotia,  and  about  Hudson's  Bay,  reaching  70-SO  ft.  high.  It  is  iiuiversally  pre- 
ferred in  America  for  ships'  yards,  and  imported  into  England  for  the  same  purpose.  It 
unites  in  a  higher  degree  all  the  good  qualities  of  the  Black  Spruce. 

Stopperwood  is  principally  used  for  piles  and  for  wheel  spokes.  It  is  a  very  strong 
and  durable  wood,  and  grows  from  12  to  IG  ft.  long  and  from  G  to  8  in.  in  dinm.  It  is 
found  on  all  the  Bahamian  islands,  and  is  an  exceedingly  hard,  fine,  close-grained,  and 
very  heavy  wood. 

Stringy-bark  (Eucali/ptus  gigantea). — This  tree  affords  one  of  the  best  building  woods 
of  Australia,  being  ckaner  and  straighter-graiued  than  most  of  the  other  species  of 
Eucahjpfus.  It  is  hard,  heavy,  strong,  close-grained,  and  works  up  well  for  planking, 
beams,  joists,  and  flooring,  but  becomes  more  difficult  to  work  after  it  dries,  and  shrinks 
considerably  in  drying.  The  outer  wood  is  better  than  the  heart.  Its  weight  is  56  lb. 
a  cub.  ft. ;  crushing-force,  6700  lb. ;  breaking-weight,  under  500  lb.  It  is  liable  to  warp 
or  twist,  and  is  susceptible  to  dry-rot.  It  sj^lits  with  facility,  forming  posts,  rails  and 
paling  for  fences,  and  shingles  fur  roofing. 

Sycamore  or  Great  Maple  (Acer  pseudo-platanus). — This  tree,  mis-called  "  plane  " 
in  N.  England,  is  indigenous  to  mountainous  Germany,  and  very  common  in  England. 
It  thrives  well  near  the  sea,  is  of  quick  growth,  and  has  a  trunk  averaging  32  ft.  long 
and  29  iu.  diam.  The  wood  is  durable  iu  the  dry,  but  liable  to  worms ;  it  is  chiefly 
used  for  furniture,  wooden  screws,  and  ornaments.  Its  weight  is  34-42  lb.  a  cub.  ft, ; 
cohesive  force,  5000-10,000  lb. ;  strength,  81 ;  stiffness,  59;  toughness,  111.  The  wood 
is  white  when  young,  but  becomes  yellow  as  the  tree  grows  older,  and  sometimes  brown 
near  the  heart ;  the  texture  is  uniform,  and  the  annual  rings  are  not  very  distinct ;  it 
has  no  large  medullary  rays,  but  the  smaller  rays  are  distinct. 

Tamanu  (^Calophyllurn  sp.). — This  valuable  tree  of  the  S.  Sea  Islands  is  becoming 
scarce.  It  sometimes  reaches  200  ft.  high  and  20  ft.  diam.  Its  timber  is  very  useful 
for  ship-building  and  ornamental  purposes,  and  is  like  the  best  Spanish  mahogany. 

Tanekaha  or  Celery-leaved  Pine  {Phyllocladus  trichomanoides)  is  a  slender,  handsome 
tree,  60  ft.  high,  but  rarely  exceeding  3  ft.  in  diam.,  afibrding  a  pale,  close-grained  wood, 
excellent  for  planks  and  spars,  and  resisting  decay  in  moist  positions  in  a  remarkable 
manner.  It  grows  in  the  hilly  districts  of  the  North  Island  of  New  Zealand,  and  iu 
Tasmania. 

Tasmauian  Blyrtle  (Fagus  Cunninghamii)  exists  in  great  abundance  throughout  the 
western  half  of  the  island,  growing  in  forests  to  a  great  size  in  humid  situations.  It 
reaches  a  height  of  60-180  ft.,  a  diam.  of  2-9  ft.,  averaging  about  3j  ft.,  and  has  a  sp.  gr. 
of  0"  795.  Its  price  is  about  IGs.  per  100  ft.  super,  in  the  log.  It  is  found  in  considerable 
quantities  in  some  of  the  mountainous  parts  iu  South  Victoria.  It  is  a  reddish-coloured 
wood,  and  much  employed  by  cabinet-makers  for  various  articles  of  furniture.  Occasion- 
ally planks  of  it  are  obtained  of  a  beautiful  grain  and  figure,  and  when  polished  its 
highly  ornamental  character  is  sure  to  attract  attention.  It  is  also  used  for  the  cogs 
of  wheels  by  millwi  ights. 

Tawa  {Xesodaphne  taica). — A  lofty  forest  tree,  60-70  ft.  high,  with  slender  branches. 
The  wood  is  light  and  soft,  and  is  nmeh  used  for  making  butter-kegs.  Grows  in  the 
northern  parts  of  the  South  Island,  and  also  on  the  North  Island  of  New  Zealand, 
chiefly  on  low  alluvial  grounds  ;  is  commonly  found  forming  large  forests  in  river  flats. 
The  wood  makes  fairly  durable  flooring,  but  does  not  last  out  of  doors. 

Tawhai  or  Tawhai-raie-nui  (Fagus  fusca). — Black  birch  of  Auckland  and  Otago 
(from  colour  of  bark).  Eed  birch  of  Wellington  and  Nelson  (from  colour  of  timber). 
This  is  a  noble  tree,  60-90  ft.  high,  the  trunk  5-8  ft.  in  diam.    The  timber  is  excessively 


Caupentey — Woods.  149 

tougli  and  hard  fo  cut.  It  is  hi-lily  valued  in  Nelson  and  \Vcllin,c;ton  as  being  Loth 
strong  and  duraljle  iu  all  situations.  It  is  found  from  Kaitaia  in  tln^  North  Island  to 
Otago  in  the  South  Island  of  New  Zealand,  hut  often  locally  absent  from  e.xtensive 
districts,  and  grows  at  all  heights  up  to  3000  ft. 

Tviik  (TcrAoiia  gmniliK'). — This  tall,  straight,  rapidly-growing  tree  inhabits  the  dry 
elevated  districts  of  the  Malabar  and  Coromaudel  coasts  of  India,  as  well  as  Burma, 
Pegu,  Java,  and  Ceylon.  Its  wood  is  light,  easily  worked,  strong,  and  durable ;  it  is  the 
best  for  carpentry  where  strength  and  durability  are  required,  and  is  considered  foremost 
for  ship-building.  The  Moulmein  product  is  much  superior  to  the  Malabar,  being 
lighter,  more  flexible,  and  freer  from  knots.  The  Vindhyan  excels  that  of  Pegu  in 
strength,  and  in  bcauly  for  cabinet-making.  The  Johore  is  the  heaviest  and  strongest, 
and  is  well  suited  for  sleejsers,  beams,  and  piles.  It  is  unrivalled  for  resisting  worms 
and  ants.  Its  weight  is  45-G2  llx  a  cub.  ft.  ;  cohesive  force,  13,000-15,000  lb. ;  strength, 
109 ;  stiffness,  12G  ;  toughness,  94.  It  contains  a  resinous  aroniatic  substance,  which 
has  a  preservative  effect  on  iron.  It  is  subject  to  heartshake,  and  is  often  damaged. 
The  resinous  secretion  tends  to  collect  and  harden  in  the  shakes,  and  will  then  destroy 
the  edge  of  any  tool.  "When  the  resinous  matter  is  extracted  during  life  by  girdling  the 
tree,  the  timber  is  much  impaired  in  elasticity  and  durability.  Teak  is  sorted  in  the 
markets  according  to  size,  not  quality.  The  logs  are  23-40  ft.  long,  and  their  width  on 
tlie  larger  sides  varies  according  to  the  class,  as  follows  : — Class  A,  15  iu.  and  upwards  ; 
Bj  12  and  under  15  in. ;  C,  under  12  in. ;  D,  damaged  logs. 

litold {Alertryonexcelsum). — A  beautiful  tree  with  trunk  15-20  ft.  high  and  12-20  in. 
diam.  AVood  has  similar  properties  to  ash,  and  is  used  for  similar  jnirposes.  Its  tough- 
ness makes  it  valuable  for  wheels,  coach-building,  &c.  Grows  in  the  North  and 
Middle  Islands  of  New  Zealand,  not  uncommon  in  forests. 

Toon,  Chittagong-wood,  or  Pied  Cedar  (Ccdrela  Toona). — Tliis  tree  is  a  native  of 
Bengal  and  other  parts  of  India,  wliere  it  is  highly  esteemed  for  joinery  and  furniture, 
measuring  sometimes  4  ft.  diam.,  and  somewhat  resembling  mahogany.  Its  weight  is  35  lb. 
a  cub.  ft. ;  cohesive  force,  4992  lb. ;  breaking-weight,  5G0  lb.  It  is  found  in  abundance  in 
Queensland,  on  the  coast  and  inland,  reaching  100-150  ft.  in  height,  and  24-7G  in.  i". 
diam.  The  wood  is  light  and  durable;  it  is  largely  employed  in  furniture  and  joinery- 
work,  and  beautiful  veneers  arc  obtained  from  the  junctions  of  the  branches  with  the 
stem.  Its  value  runs  from  loOs.  to  170s.  per  1000  ft.  super.  In  Assam  this  timber  is 
reckoned  one  of  the  most  important,  and  is  employed  for  making  canoes  and  furniture. 
It  is  higlily  spoken  of  for  making  tea-chests  in  India  and  Ceylon,  being  light,  strong, 
clean,  non-resiuous,  not  attacked  by  insects,  and  giving  no  unpleasant  odour  or  flavour 
to  the  tea.  It  grows  to  an  immense  size ;  one  tree  alone  lias  been  known  to  yield 
80,000  ft.  of  fine  timber.  It  stands  the  test  of  climate  well,  and  does  not  require  the 
same  amount  of  seasoning  as  blackwood;  it  is  of  a  much  softer  nature,  but  takes  a  very 
fine  polish,  and  is  suitable  for  dining-room  furniture,  &c. 

Totara  (_Podocarpus  Totara). — This  tree  is  fairly  abundant  in  the  North  and  South 
Islands  of  New  Zealand,  reaching  80  ft.  high  and  2i-33  ft.  diam.  Its  wood  is  easily 
worked,  straight  and  even-grained,  warjis  little,  and  splits  very  clean  and  free;  but  it  is 
brittle,  apt  to  shrink  if  not  well  seasoned,  and  subject  to  decay  in  the  heart.  It  is  used 
generally  for  joinery  and  house-building.  Its  weight  is  40  lb. ;  breaking-weight,  5701b. 
The  timber  is  reddish-coloured,  and  much  employed  for  telegraph  poles  ;  it  is  extensively 
used  in  Wellington  for  house-building,  piles  for  marine  wharves,  bridges,  railway  sleepers, 
&c.  When  felled  during  the  growing  season,  the  wood  resists  for  a  longer  time  the 
attacks  of  teredo  worms.  It  is  durable  as  fencing  and  shingles,  post  and  rail  fences 
made  of  it  being  expected  to  last  40-50  years.  The  Maoris  made  their  largest  canoes 
from  this  tree,  and  the  palisading  of  their  pahs  was  constructed  almost  entirely  of  it. 
Timber  from  trees  growing  on  hills  is  found  to  be  the  more  durable. 

Towai  or  Red  Birch  (^Fagus  Menziesii)  is  a  handsome  tree,  80-100  ft.  high,  trunk 


150  Carpentry — Woods. 

2-3  ft.  diam.  The  limber  is  chiefly  used  in  the  lake  district  of  the  South  Island  of  New 
Zealand.  Durable  and  adapted  for  mast-making  and  oars,  and  for  cabinet  and  cooper's 
Avork.  Grows  in  the  Korth  Island  on  the  mountain-tops,  but  abundant  in  the  South 
Island  at  all  altitudes  to  3000  ft. 

Tulip  (IlarpuUla  penduJa)  grows  in  Queensland  to  a  height  of  50-60  ft.,  and  yields 
planks  14-24  in.  wide,  of  close-grained  and  beautifully  marked  wood,  highly  esteemed 
for  cabinet-work. 

Walnut  (Jitrjlans  regia). — The  walnut-tree  is  a  native  of  Greece,  Asia  Minor,  Persia, 
along  the  Hindu  Kush  to  the  Himalayas,  Kashmir,  Kiunaon,  Nepal,  and  China,  and  is 
cultivated  in  Europe  up  to  55°  X.  lat.,  thriving  Ijcst  in  dr}',  deejJ,  strong  loam.  It 
reaches  CO  ft.  high  and  30-40  in.  diam.  The  young  wood  is  inferior;  it  is  in  best  con- 
dition at  about  50-CO  years.  Its  scarcity  excludes  it  from  building  application,  but  its 
beauty,  durability,  toughness,  and  otlier  good  qualities  render  it  eatei  med  for  cabinet- 
making  and  gun-stocks.  Its  weight  is  40-48  lb.  a  cub.  ft. ;  cohesive  force,  53G0-S130  lb. ; 
strength,  74;  stiffness,  49;  toughness.  111— all  taken  on  a  green  sample.  Of  the 
walnut-burrs  (or  loupes),  for  which  the  Caucasus  was  once  famous,  90  per  cent,  now 
come  from  Persia.  The  walnut  forests  along  the  Black  Sea,  which  give  excellent 
material  for  gun-stocks,  do  not  produce  burrs,  which  only  occur  in  the  drier  climates  of 
Georgia,  Daghe.-=tan,  and  Persia.     Italian  walnut  is  worth  4-5iJ.  a  ft. 

"Walnut  [Black  Virginia]  {Juglaiis  nigra). — This  is  a  large  tree  ranging  from  Penn- 
sylvania to  Florida ;  the  wood  is  heavier,  stronger,  and  more  durable  than  European 
■walnut,  and  is  well  adapted  for  naval  purposes,  being  free  from  worm  attacks  in  warm 
latitudes.  It  is  extensively  used  in  America  for  various  purposes,  especially  cabinet- 
making. 

"Willow  {Sah'x  spp.). — The  wood  of  the  willow  is  soft,  smooth,  and  light,  and  adajjted 
to  many  purposes.  It  is  extensively  used  for  the  blades  of  cricket-bats,  for  building  fast- 
sailing  sloops,  and  in  hat-making,  and  its  charcoal  is  used  in  gunpowder-making. 

Yellow- wood  or  Geel  hout  (^Taxus  elongatus). — This  is  one  of  the  largest  trees  of  the 
Cape  Colony,  reaching  6  ft.  diam.  Its  wood  is  extensively  used  in  building,  though  i-t 
warps  much  in  seasoning,  and  will  not  bear  exposure. 

Yew  {Taxus  haccata). — This  long-lived  shrubbery  tree  inhabits  Eurojie,  N.  America, 
and  Japan,  being  found  in  most  parts  of  Europe  at  1000-4000  ft.,  and  frequently  on 
the  Apennines,  Alps,  and  Pyrenees,  and  in  Greece,  Spain,  and  Great  Britain.  The 
stem  is  short,  but  reaches  a  great  diameter  (up  to  20  ft.).  The  wood  is  exceedingly 
durable  in  flood-gates,  and  beautiful  for  cabinet-making.  Its  weight  is  41-42  lb.  a  cub. 
ft. ;  cohesive  force,  8000  lb. 

As  this  volume  is  intended  as  much  for  colonial  as  for  home  readers,  it  will  be 
useful  to  give  a  brief  summary  of  the  woods  native  to  various  localities : — 

British  Guiana  Woods. — The  only  wood  from  this  colony  which  is  known  as  it 
deserves  is  the  greenheart,  already  described  at  p.  133.  Yet  there  are  several  other 
woods  equally  worthy  of  being  studied  and  utilized  ;  among  them  the  following  were 
mentioned  recently  by  Dr.  Prior  at  the  Linnean  Society.  "  Ducalibolly  "  is  a  rare  red 
wood  used  in  the  c^olony  for  furniture.  "  Hyawa-bolly  "  (Omplialohium  LamherW)  is  a 
rare  tree  20  ft.  high,  known  commercially  as  zebrawood.  Lancewood  is  variously 
referred  to  Duguetia  quitarcusis,  Guattcria  virgata,  O.cijandra  virguta,  Xi/Iopia  sj;.,  and 
Eolliiiia  Siehcri;  there  seem  to  be  2  kinds,  a  "  black"  called  curisiri,  growing  50  ft. 
liigh  and  4-8  in.  diam.,  only  slightly  taper  and  affording  by  far  the  better  timljcr,  and  a 
"yellow  "  called  "yari-yari"  (j('Jertcou  in  French  Guiana),  15-20  ft.  high  and  4-G  in. 
diam. ;  the  Indians  make  their  arrow  points  of  this  wood,  and  the  spars  go  to  America 
for  carriage  building.  Letter-wood  (^Brosimum  aulletii)  is  useful  for  inlaying  and  for 
making  very  choice  walking-sticks. 

Ca23e,  Natal,  and  Transvaal  Woods. — The  timber  trees  of  Cape  Colony  and  Natal 
are  chiefly  evergreens.     Their  wood  is  dry  and  tough,  and  worked  with  more  or  less 


CAErENTRY — Woods.  151 

difBculty.  Owing  to  tlie  dryness  of  the  soil  and  climate,  it  is  very  liable  to  warp  and 
twist  iu  seasoning.  Some  descriptions  sliriiik  longitudinally  as  well  as  transversely,  and 
with  few  exceptions  the  timber  is  not  procurable  iu  logs  of  more  than  12-15  in.  diameter. 
The  Cape  woods  principally  used  for  waggon-making,  mill  machinery,  fences,  posts,  &c., 
are  assegai  wood,  essen  wood  or  Cape  ash,  cedarwood,  red  and  white  ironwood  (excellent 
for  spokes)  ;  and  melk  wood,  red  and  white,  for  felloes  of  wheels.  These  are  principally 
brought  to  the  market  in  convenient  scantlings  for  the  purposes  for  which  tliey  arc 
requked,  and  are  all  rather  tough  than  hard  to  work.  Tiiey  have  considerable  specific 
gravity,  and  at  first  an  English  cariienter  finds  it  difficult  to  do  a  satisfactory  day's 
work  with  them.  No  European  wood  can  stand  the  heat  and  dryness  of  the  Cape 
climate  as  these  woods  do. 

Assegai-wood,  Cape  lancewood,  or  Oomhlebe :  weight,  5G  lb.  per  cub.  ft. ;  cost  of 
working  1  •  5  times  as  much  as  fir ;  colour,  light-red ;  grain,  like  lancewood ;  very 
tough  and  elastic ;  used  for  wheel-spokcs,  shafts,  waggon-rails,  assegai-shafts,  turnery. 

Cedar  boom:  weight,  41  lb.;  cost  of  working,  1-25;  used  for  floors,  roofs,  and 
other  building  jjurposes;  grain  not  unlike  Havannah  cedar,  but  of  a  lighter  colour; 
will  not  stand  exposure  to  the  weather. 

Doom  boom,  Kamcel  doom,  Makohala  or  Motootla :  weight  40  lb. ;  cost  of  work- 
ing, 1  •  25 ;  several  varieties  afl'ord  small  timber  available  for  fencing,  spars,  &c.,  and 
are  also  much  used  for  fuel,  charcoal,  &c. 

Els  (white)  or  Alder;  weight,  3S  lb. ;  cost  of  working,  1*25;  used  for  palings, 
posts,  and  ordinary  carpentry. 

Els  (red) :  weight,  47  lb.;  cost  of  working  I'G;  grain,  colour  of  red  birch;  used 
for  waggon-building  and  farm  purposes. 

Els  (rock) ;  a  harder  and  smaller  variety  of  the  last. 

Essen  hout,  Cape  ash,  or  Oomnyamati :  weight,  48  lb. ;  cost  of  working,  1  •  30 ; 
used  for  common  floors,  palings,  &c. ;  is  a  tough  and  valuable  timber,  somewhat 
resembling  elm;  can  be  procured  up  to  IS  in.  sq. 

Flat  crownwood :  cost  of  working,  1  •  30 ;  grows  in  Katal  to  2  ft.  diameter  ;  the  wood 
is  similar  to  elm,  but  of  a  bright  yellow  colour,  with  a  fine  and  even  grain ;  used  for 
the  naves  of  wheels. 

Ironwood  (black),  Tambooti,  or  Hooshe  :  weight,  64  lb. :  cost  of  working,  2*0;  the 
grain  fine,  like  pear  tree ;  used  for  waggon  axles,  cogs  of  machine  wheels,  spokes, 
telegraph  poles,  railway  sleepers,  piles,  &.c. ;  is  very  durable,  and  can  be  obtained  in 
logs  up  to  IS  ia.  sq. 

Ironwood  (white),  or  Oomzimbiti :  used  for  same  purposes  as  black. 

Kafir  boom,  Oomsinsi,  or  Limsootsi :  weight,  38  lb.  ;  wood,  soft  and  light ;  the  grain 
open  andiDorous;  splits  easily;  and  is  used  principally  for  roof  shingles,  owing  to  its 
not  being  liable  to  take  fire. 

Mangrove  (red)  :  used  in  Natal  for  posts  and  fencing  generally. 

Melk  hout,  Milkwood,  or  Oomtombi :  weight,  52  lb. ;  cost  of  working,  1  •  75  ;  colour, 
white ;  used  iu  the  construction  of  waggons  (wheelwork) ;  there  is  also  a  darker 
variety. 

Oliven  hout,  "Wild  olive,  or  Kouka;  weight,  601b.;  cost  of  working,  2*0;  wood  of 
small  size,  and  generally  deca3^ed  at  the  heart ;  used  for  fancy  turnery,  furniture,  &c. 

Pear  hout  or  Kwa :  weight,  46  lb. ;  resembles  European  pear,  but  closer  in  the 
grain. 

Safiraan  hout :  weight,  54  lb. ;  wood  strong  and  tough ;  used  for  farm  purposes. 

Sneezewood,  Nies  hout,  or  Oomtata  :  weight,  68  lb.;  cost  of  working,  3-0;  most 
durable  and  useful  timber,  resembling  satinwood ;  very  full  ot  gum  or  resin  resembling 
guaiacum  ;  burns  like  candlewood ;  invaluable  for  railway  sleepers,  pdes,  &c.,  as  it  is 
almost  imperishable,  and  is  very  useful  for  door  and  sash  sills  or  similar  work  ;  difficult 
to  be  procured  of  large  scantling. 


152  Caepentey — "Woods. 

Stinkwo(x1,  Cape  mahogany,  or  Cape  walnut:  weight,  53  lb.;  cost  of  working,  1*C; 
resembles  dark  walnut  in  grain  ;  is  used  for  furniture,  gun-stocks,  &e. ;  while  working, 
it  emits  a  peculiar  odour ;  stands  well  when  seasoned ;  usually  to  be  obtained  in  planks 
10-16  in.  wide  and  4  in.  thick ;  there  are  one  or  two  varieties  which  are  inferior ;  for 
furniture,  it  should  be  previously  seasoned  by  immersing  the  scantlings,  sawn  as  small 
as  possible,  in  a  sand  bath  heated  (o  about  100°  F.  (38°  C). 

Yellow- wood,  Geel  hout,  or  Oomkoba  :  weight,  40  lb. ;  cost  of  working,  1  •  35 ;  one  of 
the  largest  trees  that  grows  in  tlie  Cajje,  and  often  found  upwards  of  G  ft.  in  diameter  ;  the 
wood  is  extensively  used  for  common  building  jjurposes ;  it  warps  much  in  seasoning,  and 
will  not  stand  exposure  to  the  weather;  the  colour  is  alight-yellow,  which,  with  the  grain, 
resembles  lancewood;  it  shrinks  in  length  about  Jj  jjart;  it  has  ratlier  a  splintery  frac- 
tinre,  which  makes  it  very  unsafe  for  positions  where  heavy  cross  strains  may  be 
expected;  for  flooring,  it  does  well,  but  should  be  well  seasoned  and  laid  in  narrow 
widths  ;  planks  up  to  24  in.  wide  can  be  got,  but  12-in.  ones  are  more  general ;  it  suffers 
much  loss  in  conversion,  owing  to  twisting  ;  when  very  dry,  it  is  apt  to  split  in  nailing  ; 
and  is  subject  to  dry-rot  if  not  freely  ventilated. 

Willow  or  AVilge  boom  :  weight,  38  lb.  ;  this  wood,  which  grows  along  the  banks  of 
rivers,  is  of  little  value,  as  it  is  soon  destroyed  by  worms  ;  but  is  used  where  other 
timber  is  scarce ;  makes  good  charcoal. 

Ceylon  icoocls. — In  the  following  list  of  Ceylon  woods,  the  breaking-weight  and  the 
deflection  before  breaking  are  taken  on  a  bar  24  in.  long  and  1  in.  si^uare  ;  the  absorp- 
tive power  is  calculated  on  a  block  measuring  12  in.  by  4  in.  by  4  in. ;  and  the  weight 
represents  1  cub.  ft. 

Alubo ;  weight,  49  lb. ;  durability,  20  years  ;  use,  common  house-building. 

Aludel :  breaking  weight,  35U  lb.;  deflection,  1  in.:  absorption,  15  oz. ;  weight, 
51  lb.;  durability,  35-70  years;  logs  average  22i  ft.  by  IG  in.;  uses,  fishing  boats  and 
house  buildings. 

Aramana :  breaking  weight,  207  1b.;  deflection,  1^  in.;  absorption,  13  oz.  ;  weight, 
57  lb. ;  durability,  50  years ;  logs  average  15  ft.  by  13  in. ;  uses,  furniture  and  house 
buildings. 

Beriya:  weight,  57  lb.;  durability,  10-30  years:  uses,  anchors  and  house-lniilding. 

Buruta  or  Satinwood :  breaking-weight,  521  lb.  ;  deflection,  1  in. ;  absurption, 
14  oz. ;  weight,  55  lb. ;  durabilit}',  10-80  years ;  logs'average  19  ft.  by  20i  in. ;  uses,  oil- 
presses,  waggon-wheels,  bullock-carts,  bri<lges,  cog-wheels,  buildings,  and  furniture. 

Calamander  :  weight,  57  lb. ;  durability,  80  years ;  a  scarce  and  beautiful  wood ;  tiie 
most  valuable  for  ornamental  purposes  in  Ceylon. 

Darainna :  weight,  44  lb. ;  durability,  40  years  ;  uses,  gun-stocks  and  common  house 
buildings. 

Dangaha :  weight,  23  lb. ;  buoys  for  fishing  nets,  models  for  dhonies. 

Dawatu :  weight,  43  lb. ;  durability,  25  years  ;  uses,  roofs  of  common  buildings. 

Del :  breaking-weight,  2G4  lb, ;  deflection,  ^  in. ;  absorption,  17  oz. ;  weight,  40  lb. ; 
durability,  20-50  years. ;  logs  average  22J  ft.  by  16  in. ;  uses,  boats  and  buildings. 

Dun  :  weight,  29  lb.  ;  durability,  50  years  ;  uses,  house  buildings. 

Ebony :  breaking- weight,  360  lb. ;  deflection,  1|  in. ;  absorption,  11  uz. ;  weight,  71  lb. ; 
duraTaility,  80  years  ;  logs  average  12i  ft.  by  13  in.  ;  a  fine  black  wood,  used  largely  for 
buildings  and  furniture. 

Gal  Mendora:  breaking- weight,  370  lb.;  deflection,  li  in.;  absorption,  14  oz. ; 
weight,  571b. ;  durability,  15-60  years;  logs  average  22^11.  by  13  in. ;  uses,  bridges  and 
buildings ;  is  the  best  wood  for  underground  jnirposes ;  also  used  for  recpers  (battens) 
for  tiling. 

Gal  Mora :  weight,  65  lb. ;  durability,  30  years ;  uses,  housie  buildings,  and  gives  best 
firewood  for  brick-  and  lime-kilns. 

Goda^xira  :  weight,  51  lb. ;  durability,  60  years ;  use,  roofs  for  houses. 


Caepentey — Woods.  153 

Gorukina :  wciglit,  41  lb. ;  durability,  25  years ;  uses,  poles  for  bullock-carts,  and 
house  buildings. 

Hal:  weight,  2G  lb. ;  durability,  10  years  ;  uses,  packing  cases,  ceilings,  coffins. 

Hal  Mcndora :  weight,  5G  lb. ;  durability,  8-20  years ;  uses,  bridges  and  house 
buildings,  lasts  longer  than  the  jireceding  for  underground  purposes. 

Hal  Milila:  breaking-weight,  422  lb. ;  deflection,  2|  in. ;  absorption,  6  oz. ;  wciglit, 
48  lb. ;  durability,  10-80  years  ;  logs  average  20i  ft.  by  143  in- ;  "ses,  casks,  tubs,  carts^ 
waggons,  and  buildings  ;  is  the  best  wood  for  oil-casks  in  the  island. 

Hirikadol : .  weight,  49  lb.  ;  durability,  15  years  ;  use,  common  house  buildings. 

Hora:  weight,  4.51b.  ;  durability,  15  years;  use,  roofs  of  common  buildings. 

Ironwood :  breaking-weight,  497  lb. ;  deflection,  1  in. ;  absor])tion  7  oz. ;  weight,  72  lb. ; 
durability,  10-60  years ;  logs  average  22J  ft.  by  14^  in. ;  uses,  bridges  and  buildings. 

Jack  :  breaking-weight,  30G  lb. ;  deflection,  |  in.  ;  absorption,  17  oz. ;  weight,  42  lb.  ; 
durability,  25-80  years  ;  logs  average  21  ft.  by  17  in. ;  in  general  use  for  buildings,  boats, 
and  all  kinds  of  furniture. 

Kadol :  weight,  G5  lb. ;  durability,  40  years  ;  use,  common  house-building. 

Kadubberiya  or  Bastard  ebony  ;  weight,  45  lb. ;  durability,  40  j-ears  ;  use,  furniture  ; 
the  heart  of  this  wood  is  occasionally  of  great  beauty. 

Kaha  Milila  :  breaking-weight,  385  lb. ;  deflection,  1  in.  ;  absorption,  8  oz. ;  weight, 
56  lb. ;  durability,  15-80  years;  logs  average  16  ft.  by  ISi  in.  ;  uses,  water-casks,  pade- 
boats,  waggon-wheels,  bullock-carts,  bridges,  and  buildings. 

Kahata:  weight,  38  lb.  ;  durability,  10-20  years;  uses,  axles  for  bullock  bandies,  and 
buildings. 

Kalukela :  weight,  38  lb. ;  durability,  30  years  ;  uses,  common  house  buildings  ;  when 
variegated,  it  is  a  beautiful  wood,  and  is  used  for  fiu-niture  and  cabinet-work. 

Kiripella:  weight,  30  lb.;  durability,  20-30  years;  uses,  common  furniture  and 
house  buildings. 

Kiriwalla :  weiglit,  35  lb. ;  durability,  30  years  ;  uses,  principally  for  inlaying  orna- 
mental furniture  and  cabinet-work. 

Kitul :  weight;  71  lb. ;  durability,  30-90  years ;  uses,  reepers  (roof  battens)  and 
window-bars. 

Kokatiya:  weight,  56  lb. ;  durability,  80  years  ;  use,  house  buildings. 

Kon:  weight,  49  lb.;  durability,  5-10  years;  uses,  native  oil  presses  and  wooden 
anchors. 

Kottamba  :  weight,  38  lb. ;  durability,  30  years  ;  use,  common  house  buildings. ' 

Mai  Buruta :  breaking-weight,  252  lb.  ;  weight,  57  lb. ;  durability,  SO  years ;  logs- 
average  19  ft.  by  20i  in.;  use,  furniture,  being  the  most  valuable  Ceylon  wood  next  to 
Calamander. 

Mi :  breaking-weight,  362  lb.  ;  deflection,  1  in. ;  absorption,  15  oz. ;  weight,  61  lb.; 
durability,  25-80  years ;  logs  average  25  ft.  by  16  in.  ;  uses,  keels  for  dhonies,  bridges, 
and  buildings. 

Mian  Milila :  breaking-weight,  394  lb. ;  deflection,  1  in. ;  absorption,  8  oz. ;  weight, 
561b. ;  durability,  20-90  years;  logs  average  16  ft.  by  ISJ  in. ;  uses,  bridges,  pade'-boats, 
cart  and  waggon-wheels,  water-tubs,  house  buildings. 

Muruba ;  weiglit,  42  lb. ;  durability,  30-40  years ;  uses,  water  and  arrack  casks, 
buildings,  and  underground  purposes. 

Nedun  :  breaking- weight,  437  lb.  ;  deflection,  1  in. ;  absorption,  12  oz. ;  weight,  561b. ; 
durability,  60-80  years;  logs  average  15  ft.  by  16  in.  ;  uses,  buildings  and  furniture. 

Nelli :  weight,  49  lb. ;  durability,  30  years ;  uses,  wheels  and  wells. 

Pol  or  Coconut :  weight,  70  lb. ;  durability,  20-50  years ;  uses,  buildings,  fancy  boxes, 
and  furniture. 

Sapu:  weight,  42  lb.;  durability,  20-50  years;  uses,  carriages,  palankins,  &c. ;  in 
buildings  it  is  a  very  good  wood  for  window-sashes. 


154  Carpentry — Woods. 

Sapu  Milila:  weiglit,  49  lb.;  durability,  10-40  years;  use?,  water-casks,  cart  and 
■waggon  wheels,  pade-boats,  bridges,  aud  house  buildings. 

Suriya :  breaking-weight,  354  lb. ;  deflection,  li  in. ;  absorption,  IG  oz. ;  weight, 
49  lb.;  durability,  1^0-40  years;  logs  average  12  ft.  by  IG  in.;  uses,  admirable  for 
■carriages,  hackeries,  gun-stocks,  and  in  buildings. 

Tal :  breaking-weight,  407  lb. ;  dellection,  f  in. ;  absorption,  13  oz. ;  weight,  G5  lb. ; 
durability,  SO  years ;  uses,  rafters  and  reepers  (battens  for  roofs). 

Teak:  breaking- weight,  33G  lb.  ;  deflection,  |  in. ;  absorption,  13  oz. ;  weight,  44  lb.; 
•durability,  15-90  years;  logs  average  23  ft.  by  ITJ  in.;  uses,  carts,  waggons,  bridges, 
buildings,  and  arrack  casks,  imparting  fine  colour  and  flavour  to  the  liquor. 

Ubbariya :  breaking-weight,  232  lb. ;  weight,  51  lb. ;  durability,  SO  years ;  uses, 
lafters  and  reepers. 

Velanga :  weight,  3G  lb. ;  uses,  poles  of  bullock-carts,  betel  trays,  and  gun-stocks. 

Walbombu:  weight,  36  lb. ;  durability,  15  years;  use,  common  liouse  buildings. 

Waldomba:  weight,  39  lb.;  durability,  20  years;  use,  common  house  buildings. 

Walukina:  weight,  39  lb. ;  durability,  10  years;  use,  masts  of  dhonies. 

Welipenna:  weight,  35  lb.;  durability,  40  years;  use,  common  house  buildings. 

Wewarana  :  weigiit,  C2  lb. ;  durability,  60  years ;  uses,  house  buildings  and  pestles. 

English  icoods. — The  spruce  fir  of  Oxfordshire  is  used  for  scafibld-poles,  common 
carpentry,  &c. ;  the  maple  of  the  same  county  is  valuable  for  ornamental  work  when 
knotted,  it  makes  the  best  charcoal  aud  turns  well.  The  Wandsworth  sycamore  is  used 
in  dry  carpentry,  turns  well  and  takes  a  fine  polish.  The  Wandsworth  horse-chestnut 
is  used  for  inlaying  toys,  turnery,  and  dry  carpentry.  The  Oxfordshire  alder  for 
common  turnery  work,  &c.,  and  lasts  long  under  water  or  buried  in  the  ground.  The 
Killarncy  arbatus  is  hard,  close-grained,  and  occasionally  used  by  turners ;  the  Killarney 
barberry  is  chiefly  used  for  dyeing.  The  common  birch  of  Ep^^ing  is  inferior  in  quality, 
but  much  used  in  the  North  of  England  for  herring  barrels.  The  Epping  hornbeam  is 
very  tough,  makes  excellent  cogs  for  wheels,  and  is  much  valued  for  fuel.  Cornwall 
chestnut  is  valuable  in  ship-buHding,  and  is  much  in  repute  for  posts  and  rails,  hop-poles, 
&c.  Cedar  of  Lebanon  makes  good  furniture,  and  is  sometimes  employed  for  ornamental 
joinery  work.  The  common  cherry  is  excellent  for  common  furniture,  and  much  in 
repute ;  it  works  easily,  and  takes  a  fine  polish.  The  young  wood  of  the  common  nut 
is  used  for  fishing  rods,  walking  bticks,  &c.  The  Epping  white  thorn  is  hard,  firm,  and 
susceptible  of  a  fine  polish ;  that  of  Mortlake  is  fine-grained  and  fragrant,  and  very 
durable.  Oxfordshire  common  laburnum  is  hard  and  durable,  and  much  used  by  turners 
and  joiners.  Lancewood  is  hard  and  fine-grained,  and  makes  excellent  skewers.  Oxford- 
shire common  beech  is  much  used  for  common  furniture,  for  handles  of  tools,  wooden 
vessels,  &c.,  and  when  kept  dry  is  durable.  Oxfordshire  common  ash  is  very  tough  and 
■elastic.  It  is  much  used  by  the  coachmaker  and  wheelwright,  and  for  the  making  of 
oars.  Holly  is  the  best  whitewood  for  Tunbridge  ware,  turns  well,  and  takes  a  very 
£ne  polish.  The  common  walnut  of  Sussex  is  used  for  ornamental  furniture,  is  much  in 
repute  for  gun-stocks,  and  works  easily.  Oxfordshire  larch  is  excellent  for  house  car- 
pentry and  ship-building  ;  it  is  durable,  strong,  and  tough.  Mortlake  common  mulberry 
is  sometimes  worked  up  into  furniture,  and  is  useful  to  turners,  but  is  of  little  durability. 
Silver  fir  is  used  for  house  carpentry,  masts  of  small  vessels,  &c.  Oxfordshire  pine 
makes  good  ratters  and  girders,  and  supplies  wood  for  house  carpentry.  The  Wands- 
worth plane  is  an  inferior  wood,  but  is  much  used  in  the  Levant  for  furniture.  The 
damson  of  that  part  is  hard  and  fine-grained,  but  not  very  durable,  and  is  suitable  for 
turning.  The  laurel  is  hard  and  compact,  taking  a  good  polish.  The  Yorkshire  moun- 
tain ash  is  fine-graineil,  hard,  and  takes  a  good  polish,  and  is  of  great  value  for  turnery, 
and  for  musical  instruments.  Yorkshire  crab  is  hard,  close-grained,  and  strong.  Epping 
service-tree,  hard,  fine-grained,  and  compact,  and  much  in  repute  by  millwrights  for 
•cogs,  friction  rollers,  &c.      Wandsworth   evergreen  oak  is  very  shaky  when  aged,  is 


Carpentry — "Woods.  155 

strong  and  ilurable,  and  makes  an  excellent  charcoal,  Sussex  oak  is  miicli  esteemed  for 
sliip-buildiug,  and  is  the  strongest  and  most  durable  of  British  woods.  "Welsh  oak  is  a 
good  wood  for  ship-buildiug,  but  is  said  to  be  inferior  to  the  common  oak.  Epping  com- 
mon acacia  is  much  used  for  treenails  in  sliip-building,  and  in  the  United  States  is  much 
in  repute  for  posts  and  rails.  Surrey  white  willow  is  good  fur  toys,  and  used  by  the 
millwright ;  it  is  tough,  elastic,  and  durable.  Oxfordshire  palm  willuw  is  tough  and 
elastic,  is  much  used  for  handles  to  tools,  and  makes  good  hurdles.  Oxfordshire  crack 
willow  is  light,  pliant,  and  tough,  and  is  said  to  be  very  durable.  The  yew  is  used  for 
making  bows,  chairs,  handles,  &c. ;  the  wood  is  exceedingly  durable,  very  tough,  elastic, 
and  fine-grained.  Wandsworth  common  lime  is  used  for  cutting  blocks,  carving,  sound- 
ing boards,  and  toys.  English  elm  is  used  in  ship-building,  for  under-water  planking, 
and  a  variety  of  other  purposes,  being  very  durable  when  kept  wet,  or  buried  in  the 
earth  ;  and  Oxfordshire  wj'ch  elm  is  considered  better  than  common  elm,  and  is  used  in 
carpentry,  ship-building,  &c._  Specimens  of  the  above  were  shown  at  the  Great  Exhibi- 
tion of  1SG2.  Of  course,  the  list  is  far  from  being  exhausted,  still  sufficient  has  been 
said  to  give  an  idea  of  the  various  uses  to  which  our  home-grown  wood  can  be  put. 

Indian  woods. — In  the  following  descriptions  of  Indian  woods,  the  "weight"  denotes 
that  of  1  cub.  ft.  of  seasoned  timber,  "  elasticity "  is  the  coefficient  of  elasticity, 
'•  cohesion  "  is  the  constant  of  direct  cohesion  in  lb.  per  sq.  in.,  "  strength  "  is  the  con- 
stant of  strength  in  lb.  for  cross  strains. 

Abies  Smithiana :  furnishes  a  white  wood,  easily  sjjlit  into  planks,  but  not  esteemed 
as  either  strong  or  durable ;  used  as  "  shingle  "  for  roof  coverings. 

Acacia  arabica :  weight  54  lb. ;  elasticity,  41SG ;  cohesion,  1G,S15  lb.  ,•  strength, 
SS4  lb. ;  seldom  attains  a  height  of  40  ft.,  or  4  ft.  in  girth  :  its  wood  is  close-gruiued 
and  tough ;  of  a  pale-red  colour  inclining  to  brown ;  can  never  be  had  of  large  size, 
and  is  generally  crooked  ;  used  for  spokes,  naves,  and  felloes  of  wheels,  ploughshares, 
tent  pegs. 

Acacia  Catechu :  weight,  5G-G0  lb. ;  a  heavy,  close-grained,  and  brownish-red  wood, 
of  great  strength  and  dmability  ;  employed  for  posts  and  uprights  of  houses,  spear  and 
sword  handles,  ploughs,  pins  and  treenails  of  cart-wheels ;  but  rarely  available  for 
timber. 

Acacia  elata:  weight,  C9  lb. ;  elasticity,  292G;  cohesion,  9518  lb. ;  strength,  695  lb. ; 
fuinishing  logs  20-o0  ft.  long,  and  5-G  ft.  in  girth ;  wood  red,  hard,  strong,  and  very 
durable ;  used  in  posts  for  buildings,  and  in  cabinet-work. 

Acacia  leucophloea:  weight,  55  lb. ;  elasticity,  40SG  ;  cohesion,  1G,2SS  lb. ;  strength, 
SGI  lb. ;  resembles  A.  arahica  and  has  similar  uses. 

Acacia  modesta:  very  hard  and  tough  timber,  suitable  for  making  mills,  &c. 

Acacia  spcciosa :  weight,  55  lb. ;  elasticity,  35U2 ;  strength,  GOO  lb. ;  grows  to 
40-50  ft.  in  height  and  b-Q  ft.  in  girth  :  the  wood  is  said  by  some  write-rs  to  be  hard, 
strong,  and  durable,  never  warping  or  cracking,  and  to  be  used  by  the  natives  of  Soutli 
India  for  naves  of  wheels,  pestles  and  mortars,  and  for  many  other  purposes;  but  in 
Northern  India  it  is  held  to  be  brittle,  and  fit  only  for  such  purposes  as  bos  planks  and 
firewood. 

Acacia  stipulata :  weight,  50  lb.;  elasticity,  4474;  cohesion,  21,41G  lb.;  strength, 
823  lb. ;  furnishes  large,  strong,  compact,  stilf,  fibrous,  coarse-grained,  reddish -brown 
timber,  well  suited  for  wheel  naves,  furniture,  and  house-building. 

Adenauthera  pavonina:  weight,  55  1b.;  elastisity,  3103  1b.;  cohesion,  17,846  lb.  ; 
strength,  SG3-10G0  lb. ;  timber  does  not  enter  the  market  in  large  quantities ;  is  stnjiig, 
but  not  stiif ;  hard  and  durable,  tolerably  close  and  even-grained,  and  stands  a  good 
polish ;  when  fresh  cut,  it  is  of  beautiful  red  coral  colour,  with  a  fragrance  somewhat 
resembling  sandalwood ;  after  exposure  it  becomes  purple,  like  rosewood ;  used  some- 
times as  sandalwood,  and  adapted  for  cabinet-making  purposes. 

Ailauthus  excelsa  :  wood  is  white,  light,  and  not  durable  ;  used  for  scabbards,  &c. 


156  Carpentry — "Woods. 

Albizzia  elata :  weight,  42-55  lb. ;  used  by  the  Burmese  for  bridges  and  house-posts  ; 
it  has  a  large  proportion  of  sapwood,  but  the  heartwood  is  hard  and  duralile ;  may 
eventually  become  a  valuable  article  of  trade. 

Albizzia  stipulata :  weight,  G6  lb. ;  has  a  beautifully  streaked  brown  heartwood, 
which  i.s  much  prized  for  cart-wheels  and  bells  for  cattle. 

Albizzia  sp.  (Kokoh) :  weight,  4G  lb. ;  elasticity,  4123 ;  cohesion,  19,2G3  lb.  ; 
strength,  855  lb. ;  much  valued  by  the  Burmese  for  cart-wheels,  oil-presses,  and 
canoes. 

Artocarpus  hirsuta  (Anjilli)  :  weight,  40  lb. ;  elasticity,  3905  ;  cohesion,  15,070  lb. ; 
strength,  744  lb. ;  especially  esteemed  as  a  timber  bearing  submersion  in  water;  durable, 
and  much  sought  after  for  dockyards  as  second  only  to  teak  for  ship-building  ;  also  used 
for  house-building,  canoes,  &c. 

Artocarpus  integrifolia  (Jack):  weight,  44  lb.;  elasticity,  4030;  cohesion 
16,420  lb. ;  strength,  7S8  lb. ;  wood  when  dry  is  brittle,  and  has  a  coarse  and  crooked 
grain ;  is,  however,  suitable  for  some  kinds  of  house  carpentry  and  joinery ;  tables, 
musical  instruments,  cabinet  and  marquetry  work,  &c. ;  wood  when  first  cut  is  yellow, 
afterwards  changing  to  various  shades  of  brown. 

Artocarpus  Lacoocha  (Monkey  Jack) :  weight,  40  lb. ;  wood  used  in  Burma  for 
canoes. 

Artocarpus  mollis  :  weight,  30  lb. ;  used  for  canoes  and  cart-wheels. 
Azadirachta  indica  (Xeem) :  weight,  50  lb. ;  elasticity,  2G72-3183 ;  cohesion, 
17,450  lb. ;  strength,  720-752  lb. ;  wood  is  hard,  fibrous,  and  durable,  except  from 
attacks  of  insects;  it  is  of  a  reddish-brown  colour,  and  is  used  by  the  natives  for  agricul- 
tural and  building  purposes;  is  difficult  to  work,  but  is  worthy  of  attention  for  orna- 
mental woodwork  ;  long  beams  are  seldom  obtainable  ;  but  the  short  thick  planks  are  in 
much  request  for  doors  and  door-frames  for  native  houses,  on  account  of  the  fragrant 
odour  of  the  wood. 

Bariingtonia  acntangula :  weight,  56  lb.;  elasticity,  400G ;  cohesion,  10, SCO  lb.; 
strengtlj,  8G3  lb.  ;  wood  of  a  beautifully  red  colour,  tough  and  strong,  with  a  fine  grain, 
and  susceptible  of  good  polish ;  used  in  making  carts,  and  is  in  great  request  by  cabinet- 
makers. 

Barringtonia  racemosa ;  weight,  56  lb.:  elasticity,  3845;  cohesion,  17,705  lb.; 
strength,  819  lb. ;  wood  is  lighter  coloured,  and  close-grained,  but  of  less  strength  than 
that  of  the  last-named  species ;  used  for  house-building  and  cart-framing,  and  has  been 
employed  for  railway-sleepers. 

B;iss;a  latifolia :  weight,  66  lb. ;  elasticity,  3420 ;  cohesion,  20,070  lb. ;  strength, 
760  lb. ;  wood  is  sometimes  used  for  doors,  windows,  and  furniture  ;  but  it  is  said  to  be 
eagerly  devoured  by  wliite  ants. 

Bassia  longifolia  :  weight.  GO  lb. ;  elasticity,  3174  ;  cohesion,  15,070  lb. ;  strength, 
730  lb. ;  is  used  for  spars  in  Malabar,  and  considered  nearly  equal  to  teak,  though 
smaller. 

Bauhinia  variegata :  centre  wood  is  hard  and  dark  like  ebony,  but  seldom  large 
enough  for  building  purposes. 

Berrya  ammonilla  (Trincomallie) :  weight,  50  lb.  ;  elasticity,  3836 ;  cohesion, 
26,704  lb. ;  strength,  784  lb. ;  most  valuable  wood  in  Ceylon  for  naval  purposes,  and 
furnishes  the  material  of  the  Madras  Masoola  boats ;  considered  the  best  wood  for 
capstan  bars,  crosstrees,  and  fishes  for  masts  ;  is  light,  strong,  and  flexible,  and  takes  the 
place  of  ash  in  Southern  India  for  shafts,  helves,  &c. 

Bignonia  chelonoides  :  weight,  48  lb. ;  elasticity,  2804  ;  cohesion,  16,657  lb. ;  strength, 
642  lb. ;  wood  is  liighly  coloured  orange-yellow,  hard,  and  durable ;  a  good  fancy  wood, 
and  suitable  for  building. 

Bignonia  stipulata:  weight,  64  lb.;  elasticity,  5033 ;  cohesion,  2S,99S  lb. ;  strength, 
1386  lb. ;  furnishes  logs  IS  ft.  in  length  and  4  ft.  in  girth,  with  strong,  fibrous,  elastic 


Carpentry — Woods.  157 

timber,  resembling  teak ;  used  in  house-building,  and  for  bows  and  spear-handles ;  ono 
of  the  strongest,  densest,  and  most  valuahle  of  the  Bunnan  woods. 

Bombax  heptaphyllum  :  elasticity,  2225 ;  cohesion,  GOol  lb. ;  strength,  G78  lb. ; 
light  loose-grainod  wood,  valueless  as  limber,  but  extensively  used  for  paekin"-  cases, 
teu-chests,  and  camel  trunks ;  and  as  it  does  not  rot  in  water,  it  is  useful  for  stakes  in 
canal  banks,  &c. ;  long  plauks  3  ft.  iu  width  can  be  obtained  from  old  trees. 

Borassus  llabelliforniis:  weight,  C.5  lb.;  elasticity,  490i ;  cohesion,  11,898  lb.; 
strength,  044  lb. ;  timber  is  very  durable  and  of  great  strength  to  sustain  cross  strain  ; 
used  for  rafters,  joists,  and  battens ;  trees  have,  however,  to  attain  a  considerable  ago 
before  they  are  fit  for  timber. 

Briedelia  spinosa:  weight,  GO  lb. ;  elasticity,  4132;  cohesion,  14,8011b.;  strength, 
892  lb. ;  strong,  tough,  durable,  close-grained  wood,  of  a  copper  colour,  which,  however, 
is  not  easily  worked  ;  employed  by  the  natives  fur  cart-building  and  house-beams,  and 
is  also  used  for  railway-sleepers  ;  lasts  under  water,  and  is  consequently  used  for  well- 
curbs. 

Butea  frondosa  :  wood  is  generally  small  or  gnarled,  and  used  only  for  firewood  ;  in 
Guzcrat,  however,  it  is  extensively  used  for  house  purposes,  and  deemed  durable  and 
strong. 

Buxus  nepalensis  :  a  very  valuable  wood  for  engraving,  but  inferior  to  the  Black  Sea 
kind  of  box  iu  closeness  of  grain  and  in  hardness. 

Byttneria  sp. :  weight,  G3  lb. ;  elasticity,  4284 ;  cohesion,  20,571  lb. ;  strength, 
1012  lb. ;  wood  of  great  elasticity  and  strength,  invaluable  for  gun-carriages  ;  used  by 
Burmese  for  axles,  cart-poles,  and  spear-handles. 

Cresalpinia  Sappau  :  weight,  GO  lb. ;  elasticity,  4790 ;  cohesion,  22,578  lb. ;  strength, 
15401b.;  admirably  adapted  for  ornamental  work,  being  of  a  beautiful  "flame"  colour, 
with  a  smooth  glassy  surface,  easily  worked,  and  neither  warping  nor  cracking. 

Calophyllum  angustifolium :  weight,  45  1b.;  elasticity,  2944 ;  cohesion,  15,861  lb. ; 
strength,  C12  lb. ;  see  Poon,  p.  145. 

Calophyllum  longifolium:  weight,  45  lb.;  elasticity,  3491;  cohesion,  16,388  lb.; 
strength,  54G  lb. ;  a  red  wood,  excellent  for  masts,  helves,  &c.,  and  also  (when  well 
cleaned  and  polislied)  for  furniture  ;  but  it  does  not  appear  to  be  abundant. 

Careya  arborea :  weight,  50-56  lb. ;  elasticity,  3255  ;  cohesion,  14,803  lb. ;  strength, 
G75-S70  lb. ;  furnishes  a  tenacious  and  durable  wood,  which  admits  of  a  line  polish  ; 
does  not,  however,  appear  to  be  much  used  as  timber,  except  in  Pegu,  where  it  grows 
to  a  very  large  size,  and  is  the  chief  material  of  which  the  carts  of  the  country  are 
made,  and  the  red  wood  is  esteemed  equivalent  to  mahogany. 

Casuarina  muricata :  weight,  55  lb. ;  elasticity,  4474 ;  cohesion,  20,887  lb. ;  strength, 
920  lb. ;  yields  a  strong,  fibrous,  stiff  timber,  of  reddish  colour. 

Cathartocarpus  Fistula:  weight,  41  lb.;  elasticity,  3153;  cohesion,  17,705  lb.; 
strength,  846  lb. ;  generally  a  small  tree,  whose  close-grained,  mottled,  dark-brown  wood 
is  suited  for  furniture ;  iu  Malabar,  however,  it  grows  large  enough  to  be  used  for  spars 
of  native  boats. 

Cedrela  Toona  :  weight,  31  lb. ;  elasticity,  2684-3568 ;  cohesion,  9000  11>. ;  strength, 
560  lb. ;  see  Toon,  p.  149. 

Cedrus  Deodara:  elasticity,  3205-3925  ;  strength,  456-625  lb. ;  see  Deodar,  p.  132. 

Chickrassia  tabiUaris  :  weight,  42  lb. ;  elasticity,  2876 ;  cohesion,  9943  lb. ;  strength, 
614  lb. ;  stronger  and  tougher  than  Toon  (p.  149),  but  very  liable  to  warp ;  used  as 
maho;;any  by  cabinet-makers. 

Chloroxylon  Swietenia :  weight,  GO  lb.;  elasticity,  4163;  cohesion,  11,369  lb.; 
strength,  870  lb. ;  see  Satinwood,  p.  147. 

Cocos  nucifera  :  weight,  70  lb. ;  elasticity,  3605 ;  cohesion,  9150  lb. ;  strength, 
608  lb.  ;  gives  a  hard  and  durable  wood,  fitted  for  ridge-poles,  rafters,  battens,  posts, 
pipes,  boats,  &c. 


158  Caepentry — Woods. 

Connaras  speciosa :  heavy,  strong,  white  timber,  adapted  to  every  purpose  of  house- 
biiilding. 

Conocarpus  acuminatus  :  weight,  59  lb. ;  [elasticity,  4352 ;  cohesion,  20,623  lb. ; 
strength,  880  lb. ;  heartwood  is  reddish  brown,  hard,  and  durable ;  used  for  house  and 
cart  building;  exposed  to  water,  it  soon  decays. 

Conocarpus  latifolius  :  weight,  Go  lb. ;  elasticity,  5033  ;  cohesion,  21,155  lb. ;  strength, 
1220  lb. ;  furnishes  a  hard,  durable,  chocolate-coloured  wood,  very  strong  in  sustaining 
cross  strain  ;  in  Nagpore  20,000  axletreea  are  annually  made  from  this  wood  ;  it  is  well 
suited  for  carriage  shafts. 

Dalbergia  latifolia ;  weight,  50  lb. ;  elasticity,  4053  ;  cohesion,  20,283  lb. ;  strength, 
912  lb.;  perhaps  the  most  valuable  tree  of  the  Mackas  Presidency,  furnishing  the  well- 
known  Malabar  blackwood;  the  trunk  sometimes  measures  15  ft.  in  girth,  and  planks 
4  ft.  broad  are  often  procurable,  after  the  outside  white  wood  has  been  removed  ;  used 
for  all  sorts  of  furniture,  and  is  especially  valued  in  gun-carriage  manufacture. 

Dalbergia  oojeinensis  :  centre  timber  is  dark,  of  great  strength  and  toughness, 
especially  adapted  for  cart-wheels  and  ploughs. 

Dalbergia  Sissu :  weight,  50  lb. ;  elasticity,  8516-4022  ;  cohesion,  12,072-21,257  lb.  ; 
strength,  706-807  lb. ;  see  Sissu,  p.  147. 

Dilleuia  pentagyna;  weight,  70  lb. ;  elasticity,  3650 ;  cohesion,  17,053  lb. ;  strength, 
007  lb. ;  furnishing  some  of  the  Poon  spars  of  commerce  ;  wood  used  in  house  and  ship 
building,  being  close-grained,  tough,  durable  (even  under  ground),  of  a  reddish-brown 
colour,  not  easily  worked,  and  subject  to  warp  and  crack. 

Dillenia  speciosa:  weight,  45  lb.;  elasticity,  3355;  cohesion,  12,691  lb.;  strength, 
721  lb. ;  light,  strong,  light-brown  wood,  of  the  same  general  characteristics  with  the 
preceding  tree ;  used  in  house-building  and  for  gun-stocks. 
Diospyros  Ebenum :  see  Ebony,  p.  132. 

Diospyros  hirsuta :  weight,  60  lb. ;  elasticity,  4296 ;  cohesion,  19,830  lb. ;  strength, 
757  lb.  ■  see  Calamander  wood,  p.  152. 

Diospyros  melanoxylon:  weight,  81  lb.;  elasticity,  5058;  cohesion,  15,873  lb.; 
strength,  1180  1b.;  furnishing  a  valuable  wood  for  inlaying  and  ornamental  turnery; 
the  sapwood  white,  the  heartwood  even-grained,  heavy,  close,  and  black,  standing  a  high 
polish. 

Diospyros  tomentosa :  furnishing  a  hard  and  heavy  black  wood ;  young  trees  are 
extensively  felled  by  the  natives  as  cart-axles,  for  which  they  are  well  suited  from  their 
toughness  and  strength. 

Dipterocarpus  alatus :  weight,  45  lb. ;  elasticity,  3247  ;  cohesion,  18,781  lb. ;  strength, 
750  lb.  ;  timber  is  excellent  for  every  purpose  of  liouse-building,  but  if  exposed  to 
moisture  is  not  durable ;  it  is  hard  and  coarse-grained,  with  a  powerful  odour,  and  of 
light -brown  colour, 

Dipterocarpus  turbinatus  :  weiglit,  45-49  lb. ;  elasticity,  3355  ;  cohesion,  15,070  lb. ; 
strength,  762-807  lb.;  a  coarse-grained  timber  of  a  liglit-brown  colour,  not  easily 
worked,  and  not  durable ;  used  by  the  natives  for  house-building,  in  sawn  planks,  which 
will  not  stand  exposure  and  moisture. 

Emblica  officinalis  :  weight,  46  lb. ;  elasticity,  2270 ;  cohesion,  16,964  lb. ;  strength, 
562  lb. ;  furnishing  a  hard  and  durable  wood,  used  for  gun-stocks,  furniture,  boxes,  and 
veneering  and  turning ;  is  suitable  for  well-curbs,  as  it  does  not  decay  under  water. 

Erythrina  indica :  furnishes  a  soft,  white,  easily  worked  wood,  being  light,  but  of  no 
strength,  and  eagerly  attacked  by  white  ants ;  used  for  scabbards,  toys,  light  boxes  and 
trays,  &c. ;  grows  very  quickly  from  cuttings. 

Feronia  elephantura  :  weight,  50  lb. ;  elasticity,  3248 ;  cohesion,  13,909  lb. ;  strength, 
645  lb. ;  a  yellow-coloured,  hard,  and  compact  wood,  used  by  the  natives  in  house-  and 
cart-building,  and  in  some  places  employed  as  railway  sleepers. 

ricu3glomerata(Gooler):  weight,  40  lb. ;  elasticity,  2090-2113;  cohesion,  12,691  lb. ; 


Caepentry — "Woods.  159 

strength,  5SS  lb. ;  ■wood  is  light,  tongli,  ccarso-graincd,  and  brittle ;  used  for  door-pancla, 
and,  being  very  durable  under  water,  for  well-curbs. 

Ficua  indica  (Banyan) :  weight,  3G  lb.  ;  elasticity,  2S7G ;  cohesion,  91.57  lb. ;  strength, 
600  lb. ;  wood  is  brown-coloured,  light,  brittle,  and  coarse-grained,  neiilu^r  strong  nor 
durable  (except  under  water,  for  which  cause  it  is  used  for  well-curbs) ;  the  wood, 
however,  of  its  pendant  aerial  roots  is  strong  and  tough,  and  used  for  yokes,  tent- 
poles,  &c. 

Ficus  religiosa  :  weight,  3i  lb. ;  elasticity,  2371-2454  ;  cohesion,  7r)35  lb. ;  strength, 
458-581  lb, ;  similar  in  apjicarance,  characteristics,  and  uses  to  banyan. 

Gmelina  arborea:  weight,  35  lb.;  elasticity,  2132;  has  a,  pale-yellow  wood,  light, 
easily  worked,  not  shrinking  or  warping,  strong  and  durable,  especially  under  water ; 
it  is,  [however,  readily  attacked  by  white  ants ;  iised  for  furniture,  carriage  panels, 
palkees,  &c. ;  in  Burma,  for  posts  and  house-building  generally. 

Grewia  elastica :  weight,  34  lb.';  elasticity,  2S7G ;  cohesion,  17,450  lb.  ;  strength, 
5G5  lb. ;  wood  generally  is  procured  in  small  scantlings,  suitable  for  spear-shafts,  carriagc- 
and  dooly-poles,  bows,  and  tool-handles,  for  which  It  is  admirably  adapted,  being  light, 
soft,  flexible,  and  fibrous,  resembling  lancewood  or  hickory. 

Guatteria  longifolia  :  weight,  37  lb. ;  elasticity,  2SG0  ;  cohesion,  14,720  lb. ;  strength, 
547  lb. ;  wood  is  very  light  and  flexible,  but  only  used  for  drum  cylinders. 

Hardwickia  binata  :  weight,  85  lb. ;  elasticity,  4579  ;  cohesion,  12,01G  lb.  ;  strength, 
942  lb. ;  furnishing  a  red-  or  dark-coloured,  very  hard,  very  strong  and  heavy  wood, 
useful  for  posts,  pillars,  and  piles  ;  excellent  also  for  ornamental  turnery. 

Ileritiera  minor:  weight,  G4  lb.;  elasticity,  3775-4G77 :  cohesion,  29,112  lb.; 
strength,  SlG-1312  lb. ;  the  toughest  wood  that  has  been  tested  in  India,  and  stands 
without  a  rival  in  strength ;  is  used  for  piles,  naves,  felloes,  si^okes,  carriage  sliafts  and 
poles  ;  is,  however,  a  perishable  wood,  and  shrinks  much  in  seasoning. 

Ilopea  odorata  :  weight,  45-58  lb. ;  elasticity,  3GG0  ;  cohesion,  22,2091b.;  strength, 
70G-S00  lb. ;  one  of  the  finest  timber  trees  of  British  Burma,  sometimes  reaching  80  ft. 
in  height  to  the  first  branch,  and  12  ft.  in  girth — a  large  boat  of  8  ft.  beam,  and  carrying 
4  tons,  being  sometimes  made  of  a  single  scooped-out  trunk  ;  wood  is  close,  even-grained, 
of  a  light-brown  colour. 

Inga  lucida :  licartwood  is  black,  and  called  "  ironweod  "  in  Burma. 

Inga  xylocarpa :  weight,  58  lb.;  elasticity,  4283;  cohesion,  1G,G57  lb. ;  strength, 
83G  lb. ;  furnishing  a  wood  of  very  superior  quality,  heavy,  hard,  close-grained,  and 
durable,  and  of  a  very  dark -red  colour ;  it  is,  however,  not  easily  worked  up,  and  resists 
nails ;  is  extensively  used  for  bridge-building,  posts,  piles,  &c.,  and  is  a  good  wood  for 
sleepers,  lasting  (when  judiciously  selected  and  thoroughly  seasoned)  for  G  j-ears. 

Juglans  regia  (walnut) :  its  beautiful  wood  is  used  for  all  sorts  of  furniture  and 
cabinet  work  in  the  bazaars  of  the  Hill  stations. 

Lagerstra3mia  reginse :  weight,  40  lb. ;  elasticity,  3GG5 ;  cohesion,  15,388  lb. ;  strength, 
637-G42  lb. ;  the  wood  is  used  more  extensively  than  any  other,  except  teak,  for  boat-, 
cart-,  and  house-building,  and  in  the  Madras  Gun-carriage  Manufactory  for  felloes, 
naves,  framings  of  waggons,  &c. 

Mangifera  indiea  (mango) :  weight,  42  lb. ;  elasticity,  3120-3710 ;  cohesion, 
7702-9518  lb.;  strength,  5G0-632  lb.;  wood  is  of  inferior  quality,  coarse,  and  open- 
grained,  of  a  deep-grey  colour,  decaying  if  exposed  to  wet,  and  greedily  eaten  by  white 
ants  ;  is,  however,  largely  used,  being  plentiful  and  cheap,  for  common  doors  and  door- 
posts, boards  and  furniture  ;  also  for  firewood  ;  should  never  be  used  for  beams,  as  it  is 
liable  to  snap  off  short. 

Melanorhoea  usitatissima :  weight,  Gl  lb.;  elasticity,  301G;  strength,  514  lb.;  fur- 
nishes a  dark-red,  hard,  heavy,  close  and  even-grained  and  durable  (but  brittle)  timber ; 
used  for  helves,  sheave-blocks,  machinery,  railway  .sleepers,  &c. 

Melia  Azadirach ;  weight,  30  lb. ;  elasticity,  2516 ;  cohesion,  14,277  lb. ;  strength, 


160  Caepentey — Woods. 

596  lb. ;  soft,  red-coloured,  loose-textured  wood  (resembling  in  appearance  cedar),  is  used 
only  for  light  furniture. 

Miclielia  Cbampaca:  -weight,  i2  lb. ;  in  Mysore,  trees  measuring  50  ft.  in  girth  3  ft. 
■above  ground-level  are  found,  and  slabs  G  ft.  in  breadth  can  be  obtained ;  as  the  wood 
takes  a  beautiful  polish  it  makes  handsome  tables  ;  it  is  of  a  rich  brown  colour. 

IMillingtonia  hortensis :  wood  is  white,  fine  and  close-grained,  but  of  little  use. 

Mimusops  elengi:  weight,  Glib.;  elasticity,  3G53 ;  cohesion,  11,3G9  lb. ;  strength, 
632  lb. ;  wood  is  heavy,  close  and  even-graiaed,  of  a  pink  colour,  standing  a  good  polish 
and  is  used  for  cabinet-making  purposes,  and  ordinary  house-building. 

Mimusops  hexandra :  weight,  70  lb. ;  elasticity,  3948  ;  cohesion,  19,0361b. ;  strength, 
944  lb.;  furnishes  wood  very  similar  to  the  last  named;  used  for  similar  purposes,  and 
for  instruments,  rulers,  and  other  articles  of  turnery. 

Mimusops  iudica:  weight,  48  lb.;  elasticity,  4296;  cohesion,  23,824  lb. ;  strength, 
845  lb. ;  a  coarse-grained,  but  strong,  fibrous,  durable  wood,  of  a  reddish-brown  colour; 
used  for  house-building  and  for  gun-stocks. 

IMorus  iudica  (mulberry) :  wood  is  yellow,  close-grained,  very  tough,  and  well  suited 
for  turning. 

Xauelea  Cadumba:  a  hard,  deep-yellow,  loose-grained  wood,  used  for  furniture;  in 
the  Gwalior  bazaars  it  is  the  commonest  building  timber,  and  is  much  used  for  rafters 
on  account  of  cheapness  and  lightness;  but  it  is  obtiiined  there  only  in  small 
scantlings. 

Nauclea  cordifolia;  weight,  42  lb.;  elasticity,  3052-34G7;  cohesion,  10,431  lb.; 
strength,  50G-GG4  lb. ;  a  soft,  close,  even-grained  wood,  resembling  in  appearance  box, 
but  light  and  more  easily  worked,  and  very  susceptible  to  alternations  of  temperature ; 
is  esteemed  as  an  ornamental  wood  for  cabinet  purposes. 

Nauclea  parviflora :  weight,  42  lb. ;  strength,  400  lb. ;  a  wood  of  fine  grain,  easily 
worked,  used  for  flooring-planks,  packing-boxes,  and  cabinet  purposes;  much  used  by 
the  wood-carvers  of  Saharunpore. 

Phoenix  sylvestris :  weight,  39  lb. ;  elasticity,  3313 ;  cohesion,  8356  lb. ;  strength, 
512  lb. 

Picea  webbiana  :  weight,  88  lb. ;  wood  is  white,  soft,  easily  split,  and  used  as  shingle 
for  roofing,  but  is  not  generally  valued  as  timber. 

Pinus  excelsa  (Silver  Fir) :  furnishing  a  resinous  wood  much  used  for  flambeaux ; 
durable  and  close-grained ;  much  used  for  burning  charcoal  in  the  hills,  and  also  for 
building. 

Pinus  longifolia :  elasticity,  3672-4668 ;  strength,  582-735  lb. ;  being  common  and 
light,  is  largely  used  in  liouse-buiiding;  requires,  however,  to  be  protected  from  the 
weather,  and  is  suitable  for  only  interior  work  in  houses. 

Pongamia  glabra:  weight,  40  1b.;  elasticity,  3481;  cohesion,  11,104  1b.;  strength, 
G86  lb. ;  wood  is  light,  tough,  and  fibrous,  but  not  easily  worked,  yellowish  brown  in 
colour,  not  taking  a  smootli  surface ;  solid  wheels  are  made  from  this  wood ;  it  is,  how- 
ever, chiefly  used  as  firewood,  and  its  boughs  and  leaves  as  manure. 

Prosopis  spicigera:  a  strong,  hard,  tough  wood,  easily  worked. 

Psidium  pomiferum  (Guava) :  weight,  47  lb. ;  elasticity,  2676 ;  cohesion,  13,116  lb. ; 
strength,  618  1b.;  furnishes  a  grey,  hard,  tough,  light,  very  flexible,  but  not  strong 
wood,  which  is  very  close  and  fine-grained,  and  easily  and  smoothly  worked,  so  that  it 
is  fitted  for  wood-engraving,  and  for  handles  of  scientific  and  other  instruments. 

Pterocarpus  dalbergioides :  weight,  49-56  lb. ;  elasticity,  4180 ;  cohesion,  19,036  lb. ; 
strength,  864-934  lb. ;  furnishes  a  red,  mahogany-like  timber,  prized  by  the  natives 
above  all  others  for  cart-wheels,  and  extensively  used  by  Government  in  the  construction 
of  ordnance  carriages. 

Pterocarpus  Marsupium:  weight,  56  lb.;  elasticity,  4132;  cohesion,  19,94-3  lb.; 
strength,  868  lb. ;  wood  is  light-brown,  strong,  and  very  durable,  close-grained,  but  not 


Carpentky — Woods.  161 

easily  worked ;  it  is  extensively  used  for  cart-framing  and  houso-building,  but  should 
be  protected  from-wet;  also  well  fitted  for  railway  sleepers.  ; 

Pterocarpus  Santalinus  (Red  Sandal):  -weight,  70  lb.;  elasticity,  4582:  cohesion, 
19,036  lb. ;  strength,  975  lb. ;  heavy,  extremely  hard,  with  a  fine  grain,  and  ia  suitable 
for  turnery,  being  of  a  dark-red  colour,  and  taking  a  good  polish. 

Pterospermum  acerifolium :  a  dark-brown  wood  of  great  value,  and  as  strong  as  teak ; 
but  its  durability  has  not  yet  been  tested. 

Putranjiya  Eoxburghii :  wood  is  white,  close-grained,  very  hard,  durable,  and  suited 
for  turning. 

Quercus  spp.  (Oak) :  woods  are  heavy,  and  do  not  float  for  two  years  after  felling, 
hence  they  are  not  sent  down  the  rivers  into  the  plains. 

Rhus  acuminata :  furnishes  a  wood  much  valued  by  cabinet-makers  for  ornamental 
furniture :  planks  8  X  2 J  ft.  can  be  obtained  from  some  trees. 

Sautalum  album  (Sandal):  weight,  58  lb.;  elasticity,  3481;  cohesion,  19,461  lb.; 
strength,  874  lb.;  valued  tor  making  work-boxes,  and  small  articles  of  ornament;  and 
for  wardrobe-boxes,  iSrc,  where  its  agreeable  odour  is  a  preventive  against  insects. 

Sapindus  cmargmatus :  weight,  64  lb.;  elasticity,  3965;  cohesion,  15,495  lb.; 
strength,  682  lb. ;  furnishing  a  hard  wood,  which  is  not  durable  or  easily  worked,  and  is 
liable  to  crack  if  exposed;  but  is  used  by  natives  for  posts  and  door-frames,  also  for  fuel. 

Schleichera  trijuga  :  a  red,  strong,  hard,  and  heavy  wood,  used  for  oil-presses,  sugar- 
crushers,  and  axles ;  a  large  and  common  tree  iu  Burma,  where  excellent  solid  cart- 
wheels are  formed  from  it. 

Shorea  obtusa :  weight,  58  lb. ;  elasticity,  3500 ;  cohesion,  20,254  lb. ;  strength, 
730  lb. ;  a  heavy  and  compact  wood,  closer  and  darker  coloured  than  ordinary  sal,  used 
for  making  carts,  and  oil-  and  rice-mills. 

Shorea  robusta  (Sal):  weight,  55  lb.;  elasticity,  4209-4963;  cohesion,  11,521- 
18,243  lb. ;  strength,  769-880  lb, ;  furnislies  the  best  and  most  extensively  used  timber 
in  Northern  India,  and  is  unquestionably  the  most  useful  known  Indian  timber  for 
engineering  purposes ;  is  used  for  roofs  and  bridges,  ship-building  and  house-building, 
sleepers,  &c. ;  timber  is  straight,  strong,  and  durable,  but  seasons  very  slowly,  and  is  for 
many  years  liable  to  warp  and  shrink. 

Sonneratia  apetala :  yields  a  strong,  hard,  red  wood  of  coarse  grain,  used  in  Calcutta 
for  packing-cases  for  beer  and  wine,  and  ia  also  adapted  for  rough  house-building 
purposes. 

Soymida  febrifuga :  weight,  66  1b.;  elasticity,  3986;  cohesion,  15,070  1b.;  strength, 
1024  lb. ;  furnishing  a  bright-red  close-grained  wood,  of  great  strength  and  durability, 
preferred  above  all  wood  by  the  Southern  India  Hindus  for  the  woodwork  of  their 
houaes ;  though  not  standing  exposure  to  sun  and  weather,  it  never  rota  under  ground 
or  in  masonry,  and  is  very  well  suited  for  palisades  and  railway  sleepers. 

Stercuha  foetida:  weight,  28  lb. ;  elasticity,  3349;  cohesion,  10,736  1b.;  strength, 
464  lb. ;  in  Ceylon  it  is  used  for  house-building,  and  in  Mysore  for  a  variety  of  purposes, 
taking  the  place  of  the  true  Poon ;  wood  is  light,  tough,  open-grained,  easily  worked, 
not  splitting  nor  warping,  in  colour  yellowish-white. 

Syzygium  jambolanum:  weight,  48  lb. ;  elasticity,  2746 ;  cohesion,  8840  lb. ;  strength, 
600  lb. ;  brown  wood  ia  not  very  strong  or  durable,  but  is  used  for  door  and  window- 
frames  of  native  houses,  though  more  generally  aa  fuel ;  is,  however,  suitable  for  well 
and  canal  works,  being  almost  indestructible  under  water. 

Tamarindus  indica  (Tamarind) :  weight,  79  lb. ;  elasticity,  2803-3145 ;  cohesion, 
20,623  lb;  strength,  816-864  lb.;  heartwood  is  very  hard,  close-grained,  dark-red,  very 
hard  to  be  worked ;  used  for  turnery,  also  for  oil-presses  and  sugar-crushers,  mallets, 
and  plane-handles ;  ia  a  very  good  brick-burning  fuel. 

Tectona  grandis  (Teak) :  weight,  42-45  lb. ;  elasticity,  3978 ;  cohesion,  14,498- 
15,467  lb. ;  strength,  683-814  lb. ;  wood  is  brown,  and  when  fresh  cut  is  fragrant ;  very 

M 


162 


Cakpentrt — "Woods. 


Lard,  yet  light,  easily  worked,  and  though  porous,  Btrong  and  durable ;  soon  seasoned, 
and  shrinks  little ;  used  for  every  description  of  house-building,  bridges,  gun-carriages, 
ship-building,  &c. 

Terminalia  Arjuna :  weight,  54:  lb. ;  elasticity,  409-t ;  cohesion,  16,288  lb. ;  strength, 
820  lb. ;  furnishes  a  dark-brown,  heavy,  very  strong  wood,  suitable  for  masts  and  spars, 
beams  and  rafters. 

Terminalia  Belerica :  wood  is  white,  soft,  and  not  used  in  carpentry. 

Terminalia  Chebula  :  weight,  32  lb. ;  elasticity,  3108  ;  cohesion,  7563  lb. ;  strength, 
470  lb. ;  wood  is  used  in  Southern  India  for  common  house-building,  but  it  is  light  and 
coarse-grained,  possessing  little  strength,  and  liable  to  warp.  In  Burma  it  is  used  for 
yokes  and  canoes. 

Terminalia  coriacea :  weight,  CO  lb.  ;  elasticity,  4043  ;  cohesion,  22,351  lb. ;  strength, 
860  lb. ;  the  heartwood  is  one  of  the  most  durable  woods  known :  reddish-brown,  heavy, 
tough,  and  durable,  very  fibrous  and  elastic,  close  and  even-grained ;  used  for  beams 
and  posts,  wheels,  and  cart-building  generally,  and  telegraph-posts;  is  durable  under 
water,  and  is  not  touched  by  white  ants. 

Terminalia  glabra :  weight  55  lb. ;  elasticity,  3905  ;  cohesion,  20,085  lb.  ;  strength, 
840  lb. ;  furnishing  a  very  hard,  durable,  strong,  close  and  even-grained  wood,  of  a  dark- 
brown  colour,  obtainable  in  large  Bcantling,  and  available  for  all  purposes  of  house- 
building, cart-framing,  and  furniture. 

Terminalia  tomentosa :  supplies  a  heavy,  strong,  durable,  and  elastic  wood ;  is,  how- 
ever, a  difficult  timber  to  work  up,  and  splits  freely  in  exposed  situations ;  good  wood  for 
joists,  beams,  tie-rods,  &c.,  and  for  railway  purposes,  and  is  often  sold  in  the  market 
under  the  name  of  sal,  but  it  is  not  equal  to  that  wood. 

Thespesia  populuea :  weight,  49  lb. ;  elasticity,  3294  ;  cohesion,  18,143  lb. ;  strength, 
716  lb. ;  grows  most  rapidly  from  cuttings,  but  the  trees  so  raised  are  hollow-centred, 
and  only  useful  for  firewood ;  seedling  trees  furnish  a  pale-red,  strong,  straight,  and 
even-grained  wood,  easily  worked  ;  used  for  gun-stocks  and  furniture. 

Trewia  nudiflora  :  a  white,  soft,  but  close-grained  wood. 

Ulmus  integrifolia :  (Elm) :  a  strong  wood,  employed  for  carts,  door-frames,  &c. 

Zizyphus  Jujuba  :  weight,  58  lb.  ;  elasticity,  3584 ;  cohesion,  18,421  lb. ;  strength, 
672  lb. ;  red  dark-brown  wood  is  hard,  durable,  close  and  even-grained,  and  well  adapted 
for  cabinet  and  oriental  work. 

New  Zealand  Woods. — The  dimensioua  of  the  specimens  described  in  the  following 
table  were  12  in.  long,  and  1  iu.  sq. 


Greatest 

Name. 

Specific 
Gravity. 

Weight  of 
1  Cub.  Ft. 

Weight 

Carried  with 

Unimpaired 

Elasticity. 

Transverse 
Strengtk. 

lb. 

lb. 

lb. 

Hinau  {Elxocarpus  dentatus) 

•562 

33^03 

94-0 

125-0 

Kahika,  supposed  white  pine 

•502 

31-28 

57-3 

77-5 

Kahikatea,      white     pine    {Fodocar^m 

•488 

30-43 

57-9 

106-0 

dacrydioides). 

Kauri  {Dammara  australtg) 

•623 

38^96 

97-0 

165-5 

Js.a.via.ka.  (Libocedrus  Doniana)   .. 

•637 

39^69 

75^0 

120-0 

Kohekohe  {Dysoxi/lum  i^peciahile) 

•678 

42^25 

92^0 

117-4 

Kowhai  {Sophora  tetraptera) 

•8S4 

55-11 

98-0 

207-5 

Maire,  black  {Olea  Cunuiugluimii) 

1-159 

72-29 

193  0 

314-2 

Maire  (Eugenia  maire} 

•790 

49-24 

100-0 

179-7 

Mako  {Aridotelia  racemosdy 

•593 

33-62 

62-0 

122-0 

Manoao  (Dacrydium  colensoi) 

•788 

49-1 

200-0 

230-0 

Mangi,  or  mangeo  {Tetranlhera  calioaris) 

•621 

38-70 

109-0 

137-8 

Cakpentry — Woods. 


1G3 


Greatest 

V                                                                       Sp 

^ame.                                           q^_ 

ecific 
wity. 

Weight  of 
;  1  Cub.  Ft. 

Weight 

Carried  with 

Unimpaired 

Elasticity. 

Transverse 
Strength. 

lb. 

lb. 

lb. 

Mannka,  (Leptoftpermum  ericoides) 

943 

59-00 

115-0 

239-0 

Mapau,  red  {My rsine  urvillei) 

991 

01 '82 

92-0 

192-4 

Miitapo,     black    mapau    (^rutospermum 
tenui/olium) 

955 

60-14 

125-0 

243-0 

Matai  {Fodocarpus  spicatii) 

787 

49-07 

133-0 

197-2 

Miio  {Podocarpus  fcrruginea) 

658 

40-79 

103-0 

190-0 

Futhi  {Vitex  littoralis)     .. 

959 

59-5 

175-0 

223-0 

Eata,  or  ironwood  (Metrosideros  lucida)           1 

045 

65-13 

93-0 

190-0 

Rewarewa  {Knightia  excelsd) 

785 

48-92 

93-0 

lCl-0 

Kimu,  red  'pi^oX  I hicri/dium  cupressinuin) 

563 

36-94 

92-8 

140-2 

Taraire  {Nesodaphiie  turaire) 

SS8 

55-34 

99-6 

112-3 

Tawa.  {I^'esodaphue  tau-a) 

761 

47-45 

142-4 

205-5 

Tawiri-koliu-kohu,     or      white    mapau 
{Carpodetus  ferrattis)     .. 

822 

51-24 

80-0 

177-6 

Titoki  (Alectryon  excchum) 

916 

57-10 

116-0 

248-0 

Totara  (Fodocarpus  totara} 

559 

35-17 

77-0 

133-6 

Towai,  red  birch  {Fa<jiis  menziesn) 

626 

38-99 

73-6 

158-2 

Towai,  black  birch  (Fagus  fusca) 

•780 

48-62 

108-8 

202-5 

Queensland  Wood^s. — Among  the  principal  are  the  following : — 

Acacia  pendula  (Weeping  Myall):  6-12  in.  diam. ;  20-30  ft.  high;  wood  is  hard, 
possessing  a  close  texture,  and  a  rich  dark  colour. 

Barklya  syringifolia :  12-15  in.  diara. ;  40-50  ft.  high  ;  wood  hard  and  close-griiiued. 

Bauhinia  Hookeri :  10-20  in.  diam. ;  30-40  ft.  high ;  wood  is  lieavy,  and  of  a  dark 
reddish  hue. 

Bursaria  spinosa :  6-9  in.  diam. ;  20-30  ft.  high  ;  timber  is  hard,  of  a  close  texture, 
and  admits  of  a  good  polish. 

Cargillia  Australis  :  18-24  in.  diam. ;  60-80  ft.  high  ;  grain  is  close,  very  tough  and 
fine,  of  little  beauty,  but  likely  to  be  useful  for  many  purposes. 

Cupania  anacardioides  :  18-24  in.  diam. ;  SO-50  ft  high  ;  the  wood  is  not  appreciated. 

Cupania  nervosa :  12-20  in.  diam. ;   30-45  ft.  high  ;  wood  is  nicely  grained. 

Eremophila  Mitchelli  (Sandalwood) :  9-12  in.  diam. ;  20-30  ft.  high  ;  wood  is  very 
hard,  beautifully  grained,  and  very  fragrant ;  will  turn  out  handsome  veneers  for  the 
oabinet-maker. 

Erythrina  vespertUio  (Cork-tree) :  12-25  in.  diam. ;  30-40  ft.  high ;  wood  soft,  and 
need  by  the  aborigines  for  making  war-shields. 

ExccEcaria  Agallocba  (Poison  Tree):  12-14  in.  diam. ;  40-50  ft  high ;  wood  is  hard, 
and  fine-grained. 

Exocarpus  latifblia  (Broad-leaved  Cherry) :  6-9  in.  diam. ;  10-16  ft.  high ;  wood  very 
hard  and  fragrant ;  excellent  for  cabinet-work. 

Flindersia  Schottiana :  stem  12-16  in.  diam.;  60-70  ft.  high;  wood  is  soft,  and 
soon  perishes  when  exposed. 

HarpuUia  pendula  (Tulipwood) :  14-24  in.  diam. ;  50-80  ft  high ;  wood  has  a  firm 
fine  texture,  and  is  curiously  veined  in  colouring ;  much  esteemed  for  cabinet-work. 

Maba  obovata  :  10-15  in.  diam. ;  30-50  ft  high;  timber  is  hard,  fine-grained,  and 
likely  to  be  useful  for  cabinet-work. 

Melia  Azadirach  (White  Cedar) :  24r-30  in.  diam. ;  40-60  ft.  high  ;  wood  is  soft,  and 
not  considered  of  any  value. 

Owenia  venosa  (Sour  Plum.) :  8-12  in.  diam. ;  20-30  ft.  high  ;  wood  is  hard,  of  a 

reddish  colour,  and  its  great  strength  renders  it  fit  for  wheelwright  woik. 

M  2 


164 


Carpentry — "Woods. 


roilocarptis  data :  2-i-3G  in.  diam. ;  50-80  ft.  high  ;  wood  is  hard,  fine-grained, 
flexible,  and  elastic. 

Sarcocephalus  cordatus  (Leiclihardt's  Tree)  :  24-36  in.  diam. ;  60-80  ft.  lugh  ;  wood 
is  soft,  but  close-grained,  of  a  light  colour,  and  easily  worked. 

Spondias  pleiogyna  (Sweet  Plum) :  20-45  in.  diam. ;  70-100  ft.  liigli ;  the  wood  is 
hard  and  heavy,  dark-red,  finely  marked,  and  susceptible  of  a  high  polisli. 

Stenocarpus  sinuosus  (Tulip  Tree) :  18-24  in.  diam. ;  40-CO  ft.  high  ;  wood  is  very 
nicely  marked,  and  would  admit  of  a  good  polish. 

Straits  Seitkineuts  Woods, — The  specimens  experimented  on  measured  3  ft.  by  1|  ft. 
by  1^  ft. 


Name  of  Wixxl. 


Billian  Cliingy 


Billian  Wangy 


Darroo . 


Johore  Cedar 


Johore  Rosewood,"! 
or  Kayu  Merah.j 

Johore    Teak,    or' 
Ballow.  ' 


Jolotong 


>  ft 
< 

=5  -: 

"%  a 
as 

II 

J3!  — 

S.S 

GO 

s 

408 

013 

72 

-,', 

473 

1038 

61 

1 
To 

840 

1300 

40J 

s  • 

410 

616 

38 

5 

583 

952 

73 

8 

737 

1210 

29 

5 

a 

280 

732 

Remarks. 


Hard,  close-grained,  fine-fibred,  but  very 
much  inferior  to  Billian  Wangy;  of 
a  brownish  grey  colour ;  readily  at- 
tacked by  insects  and  dry  rot ;  tised 
for  flooring  joists. 

Very  hard,  durable,  heavy,  close-grained, 
fibre  long,  is  not  liable  to  be  attacked 
by  worms  or  white  ants;  beams  of 
50  ft.  l(mg  and  18  in.  square  can  be 
obtained.  Very  suitable  for  roofing 
timber,  girders,  joists,  and  timber 
bridges. 

Much  used  for  beams  of  houses  and  door 
frames ;  durable,  if  kept  either  wet  or 
dry,  but  rots  soon  if  exposed  to  sun 
and  rain ;  colour  white,  close-grained, 
fracture  long ;  has  an  agreeable  smell. 

Well  adapted  for  house-building  pur- 
poses, as  in  the  manufacture  of  doors, 
windows,  and  flooring  planks.  Frac- 
ture short,  timber  open-grained,  and 
is  not  liable  to  be  worm-eaten. 

Resembles  rosewood  in  appearance,  and 
used  largely  in  cabinet-work  and 
household  furniture. 

Well  adapted  for  permanent  sleepers, 
beams,  piles,  ship-building,  engineer- 
ing, and  general  purposes  where 
strength  and  durability  are  required. 
Piles  which  have  been  in  the  ground 
for  100  years  have  been  found  in  a 
good  state  of  preservation.  One  of 
the  few  woods  which  will  really  stand 
the  climate  of  India.  Colour  dull 
grey. 

Well  adapted  for  patterns  and  mould- 
ings, excellent  for  carving  purposes ; 
grain  very  close,  scarcely  any  knots, 
colour  whitish  yellow,  fracture  short, 
but  not  very  durable. 


Carpentry — Woods. 


165 


Name  of  Wood. 


Krangee 


Kruen 


•  •  •  • 


Kulini,  or  Johore"! 
Iron  wood.  j 


Marbow,  Murboo.'l 
or  Marraboo,      J 


P*naga 


Samaran 

Serian 

Tampenis    . . 


Tumbooeoo 


77 


50 


61 


72 


42 

47 

G7 


67 


To 


to 


s 

T(J 


Vo+ 


1% 


"3^ 


980 


472 


766 


399  to 
578 


688 


326 

438 

802 


306 


to 

c  . 


cy .— 


1339 


625^ 


1141 


894  to 
987 


1310 


532 

737i 
1599+ 


548 


Itcmarka. 


Very  hard,  close-grained,  well  adapted 
for  beams  of  every  description.  White 
ants  or  other  insects  do  not  touch  it. 
Well  adapted  for  piles  for  bridges  in 
fresh  or  salt  water;  also  used  for 
junks'  masts ;  stands  well  when  sawn, 
ranks  with  Tampe'nis  for  durability. 
Fracture  long,  fibres  tough,  colour 
dark  red. 

Close-grained,  tough  fibres,  and  re- 
sembling yellow  pine.  Used  for 
native  boats,  planks,  «S;c.  Contains  a 
kind  of  dammar-like  oleo-resin. 

Somewhat  similar  to  Ballow.     Used  for 
planking  cargo  boats ;  fracture  short ; 
makes  superior  beams  and  telegraph- 
s     posts,  as  it  lasts  well  in  the  ground. 
>Durable,  principally  used  for  furniture, 
^     readily  worked,  and  takes  polish  well  ; 
also  used  for  flooring  beams,  timber 
bridges,  carriage  bodies,  and  framing 
of  vessels ;  trees  4  ft.  diam.  are  some- 
times obtained ;  not  readily  attacked 
by    white  ants,    but    is    by    worms. 
Colour  almost  like  English  oak. 

Bright  red,  very  hard  and  durable,  well 
adapted  for  roofing  timbers,  joists,  and 
timber  work  of  bridges;  very  cross- 
grained  and  difiScult  to  work ;  can 
be  obtained  in  any  quantity  to  9  in. 
square.     Fracture  short. 

Well  adapted  for  doors,  windows,  mould- 
ing, and  other  house-building  pur- 
poses; close  and  even  grained,  dull- 
red  colour,  short  fracture,  but  liable 
to  attacks  of  white  ants. 

Of  a  dull-red  colour,  close-grained,  and 
largely  used  in  house-building,  for 
boxes,  boards,  &c. 

Very  hard,  close-grained,  red-coloured, 
long-fibred,  and  tough.  Well  adapted 
for  beams  of  every  description ;  white 
ants  and  other  insects  do  not  touch  it. 
Used  largely  for  bridge  piles  in  fresii 
or  salt  water ;  considered  one  of  the 
most  lusting  timbers  ;  warps  if  cut  in 
planks. 

Capital  for  piles,  or  for  any  wood-work 
which  is  exposed  to  the  action  of  fresh 
or  salt  water ;  not  attacked  by  worms 
or  white  ants.     Fracture  short. 


166  Carpentry — Woods. 

Tasmanian  icoods. — Ironwood,  Tasmanian  (Notelcea  ligustrina) :  exceedingly  hard, 
close-grained  ■wood,  used  for  mallets,  sheaves  of  blocks,  turnery,  &c. ;  diam.,  9-18  ia. ; 
height,  20-35  ft.;  sp.  grav.,  about  'OGS.     Not  uncommon. 

Native  Box  (Bursaria  spinosa) :  diam.,  8-12  in. ;  height,  15-25  ft. ;  sp.  grav.,  about 
•  825.     Used  for  turnery. 

Native  Pear  (Hakea  lissosperma) :  diam.,  8-12  in. ;  height,  29-30  ft. ;  sp.  grav., 
about  '675.     Fit  for  tiu-nery. 

Pinkwood  (Beyeria  viscosa) :  diam.,  G-10  in. ;  height,  15-25  ft. ;  sp.  grav.,  about 
•815.    Used  for  sheaves  of  blocks,  and  for  turnery. 

Swamp  Tea-tree  (Melaleuca  ericaefolia)  :  diam.,  9-20  in. ;  height,  20-60  ft. ;  sp.  grav., 
about  •  824.     Used  for  turnery  chiefly. 

White- wood  (Pittosporum  bioolor) ;  diam.,  8-13  in.;  height,  20-35  ft. ;  sp.  grav., 
about  •  875.     Used  in  turnery  ;  probably  fit  for  wood-engraving. 

West  Indian  tcoocls. — Crabwood  is  mostly  used  for  picture-frames  and  small  orna- 
mented cabinet-work,  &c.  It  seldom  grows  larger  than  3-4  in.  in  diam.,  and  is  a 
rather  hard,  fine,  cross-grained,  moderately  heavy -wood.  The  heartwood  is  of  a  beauti- 
fully veined  Vandyke  brown,  its  external  edge  briglit  black,  and  the  alburnum  of  a  pure 
white.  In  Trinidad,  tlie  balata  is  a  timber  extensively  used  for  general  purposes,  and 
much  esteemed.  Its  diameter  is  2-G  ft.  The  mastic  is  also  held  in  high  estimation,  and 
varies  from  2  to  4  ft.  in  diam.  The  gru-gru,  winch  is  a  palm,  yields  beautiful  veneer, 
as  also  docs  tlie  gri-gri.  For  some  of  these  trees  it  will  be  observed  there  is  no  verna- 
cular name,  consequently  the  choice  lies  between  the  native  and  the  botanical  name. 
The  heartwood  of  the  butterwood  only  is  used.  The  beauty  of  the  wood  is  well  known, 
but  it  never  attains  a  large  size.  Its  recent  layers  are  of  a  uniform  yellowish-white 
oolour.  The  carapa  bears  a  considerable  resemblance  to  cedar,  and  is  extensively  used 
and  much  esteemed.  It  is  2-3  ft.  in  diam.  The  West  Indian  cedar  of  Trinidad  is  a 
most  useful  timber,  and  is  well  deserving  the  attention  of  consumers,  as  is  also  the  copai, 
a  beautiful  and  durable  wood.  The  sope  is  a  light  wood,  resembling  English  elm,  im- 
pregnated with  a  bitter  principle,  which  preserves  it  from  the  attacks  of  insects.  It  is 
tough,  strong,  and  is  used  for  general  purposes.  In  diameter  it  ranges  from  1  to  2  ft. 
L'Angleme  is  a  strong,  hardy  wood,  exclusively  used  for  the  naves  of  wheels,  &c.  Cour- 
baril  is  a  valuable  and  abundant  timber  of  2-6  ft.  in  diam.,  and  may  be  otherwise 
described  under  the  name  of  West  India  locust.  Yorke  saran  is  a  very  hard  and  useful 
wood,  and  also  pearl  heart,  which  has  the  advantage  of  being  very  abundant,  and  runs 
from  2  to  4  ft.  in  diam.  Aquatapana  is  a  very  durable  and  curious  wood,  susceptible 
of  high  polish,  and  18-3G  in.  in  diam.  The  green,  grey,  and  black  poni  furnish  the 
favourite  timbers  of  tlie  colony,  and  produce  the  hardest  and  most  durable  of  wood. 
Their  timber  takes  a  fine  polish,  has  a  peculiar  odour,  and  is  very  abundant.  The  trees 
are  3-4  ft.  in  diam.,  and  proportionately  lofty. 

Growth  of  icood. — This  may  be  sufiiciently  explained  in  a  few  words.  A  cross 
section  of  an  exogenous  ("  outward  growing  ")  tree,  which  class  includes  all  timbers  used 
in  construction,  shows  it  to  be  made  up  of  several  concentric  rings,  called  "  annual," 
from  their  being  generally  depositeil  at  the  rate  of  1  a  }-ear ;  at  or  near  the  centre  is  a 
column  of  pith,  whence  radiate  thin  lines  called  "  medullary  rays,"  which,  in  some 
woods,  when  suitably  cut,  afibrd  a  handsome  figure  termed  "  silver  grain. "  As  the  tree 
increases  in  ago,  the  inner  layers  are  filled  up  and  hardened,  becoming  what  is  called 
duramen  or  "  heartwood  "  ;  the  remainder,  called  alburnum  or  "  sapwood,"  is  softer  and 
lighter  in  colour,  and  can  generally  be  easily  dintinguisheJ.  The  heartwood  is  stronger 
and  more  lasting  than  the  sapwood,  and  should  alone  bo  used  in  good  work.  The 
annual  rings  are  generally  thicker  on  the  side  of  the  tree  that  has  had  most  sun  and  air, 
and  the  heart  is  therefore  seldom  in  the  centre. 

Felling. — While  the  tree  is  growing,  the  heartwootl  is  the  strongest ;  but  after  the 
growth  has  stopped,  the  heart  is  the  first  part  to  decay.     It  is  important,  therefore,  that 


Carpentry — Woods.  167 

the  tree  slioiilcl  be  felled  at  the  right  age.  This  varies  with  different  trees,  and  even  in 
the  same  tree  under  different  circumstances.  The  induration  of  the  sapwood  should 
have  reached  its  extreme  limits  before  the  tree  is  felled,  but  the  period  required  for  this 
depends  on  the  soil  and  climate.  Trees  cut  too  soon  are  full  of  sapwood,  and  the  heart- 
wood  is  not  fully  hardened.  The  ages  at  which  the  undermentioned  trees  should  bo 
felled  are  as  follows  :— Oak,  60-200  years,  100  years  the  best ;  Ash,  Larch,  Elm,  50-100 
years;  Spruce,  Scotch  Fir,  70-100  years.  Oak  bark  is  sometimes  stripped  in  the 
spring,  when  loosened  by  the  rising  sap.  The  tree  is  felled  in  winter,  at  which  time 
the  sapwood  is  hardened  like  the  heart.  This  practice  improves  the  timber.  A  healthy 
tree  for  felling  is  one  with  an  abundance  of  young  shoots,  and  whose  topmost  branches 
look  strong,  pointed,  and  vigorous.  The  best  season  for  felling  is  midsummer  or  mid- 
winter in  temperate,  or  the  dry  season  in  tropical  climates,  when  the  sap  is  at  rest. 

Squaring. — Directly  the  tree  is  felled  it  should  bo  squared,  or  cut  into  scantling,  in 
order  that  air  may  have  free  access  to  the  interior. 

Features. — These  depend  greatly  upon  the  treatment  of  the  tree,  the  time  of  felling 
it,  and  the  nature  of  the  soil  in  which  it  has  grown.  Good  timber  should  be  from  the 
heart  of  a  sound  tree,  the  sapwood  being  entirely  removed,  the  wood  uniform  in  sub- 
stance, straight  in  fibre,  free  from  large  or  dead  knots,  flaws,  shakes,  or  blemishes  of  any 
kind.  If  freshly  cut,  it  should  smell  sweet ;  the  surface  should  not  be  woolly,  nor 
clog  the  teeth  of  the  saw,  but  firm  and  bright,  with  a  silky  lustre  when  planed;  a 
disagreeable  smell  betokens  decay,  and  a  dull  chalky  appearance  is  a  sign  of  bad  timber. 
The  annual  rings  should  be  regular  in  form ;  sudden  swells  are  caused  by  rind-galls ; 
closeness  and  narrowness  of  the  rings  indicate  slowness  of  growth,  and  are  generally 
signs  of  strength.  When  the  rings  are  porous  and  open,  the  wood  is  weak,  and  often 
decayed.  The  colour  should  be  uniform  throughout ;  when  blotchy,  or  varying  much 
from  the  heart  outwards,  or  becoming  pale  suddenly  towards  the  limit  of  the  sapwood, 
the  wood  is  probably  diseased.  Among  coloured  timbers,  darkness  of  colour  is  in 
general  a  sign  of  strength  and  durability.  Good  timber  is  sonorous  when  struck  ;  a  dull, 
heavy  sound  betokens  decay  within.  Among  specimens  of  the  same  timber,  the  heavier 
are  generally  the  stronger.  Timber  for  important  work  should  be  free  from  defects. 
The  knots  should  not  bo  large  or  numerous,  and  on  no  account  loose.  The  worst  posi- 
tion for  large  knots  is  near  the  centre  of  the  balk  required,  more  especially  if  forming  a 
ring  round  the  balk  at  one  or  more  points.  Though  the  sapwood  should  be  entirely 
removed,  the  heart  of  trees  having  most  sapwood  is  generally  strongest  and  best.  The 
strongest  part  of  the  tree  is  usually  that  containing  the  last-formed  rings  of  heartwood, 
so  that  the  strongest  scantlings  are  got  by  removing  no  more  rings  tlian  those  including 
the  sapwood.  Timber  that  is  thoroughly  dry  weighs  less  than  green ;  it  is  also  harder 
and  more  difficult  to  work. 

Defects. — The  principal  natural  defects  in  timber,  caused  by  vicissitudes  of  climate, 
soil,  &c.,  are: — "Heartshakes":  splits  or  clefts  in  the  centre  of  the  tree;  common  in 
nearly  every  kind  of  timber ;  in  some  cases  hardly  visible,  in  others  extending  almost 
across  the  tree,  dividing  it  into  segments;  one  cleft  right  across  the  tree  does  not  occasion 
much  waste,  as  it  divides  the  squared  trunk  into  2  substantial  balks;  2  clefts 
crossing  one  another  at  right  angles,  as  in  Fig.  217,  make  it  impossible  to  obtain  scant- 
lings larger  than  ^  the  area  of  the  tree ;  the  worst  form  of  heartshake  is  when  the  splits 
twist  in  the  length  of  the  tree,  thus  preventing  its  conversion  into  small  scantlings  or 
planks.  "  Starshakes  " :  in  which  several  splits  radiate  from  the  centre  of  the  timber, 
as  in  Fig.  21S.  "  Cupshakes  "  :  curved  splits  separating  the  whole  or  part  of  one  annual 
ring  from  another  (Fig.  219) ;  when  they  occupy  only  a  small  portion  of  a  ring  they  do  no 
great  harm.  "  Rind-galls  "  :  peculiar  curved  swellings,  caused  generally  by  the  growth 
of  layers  over  the  wound  remaining  after  a  branch  has  been  imperfectly  lopped  off. 
"Upsets":  portions  of  the  timber  in  which  the  fibres  have  been  injured  by  crushing. 
"Foxiness":  a  yellow  or  red  tinge  caused  by  incipient  decay,  "Doatiness":  a  speckled 


168 


Cakpentry — Woods. 


stain  found  in  beech,  American  oak,  and  others.  Twisted  fibres  arc  caused  by  the 
action  of  a  prevalent  wind,  turning  the  tree  constantly  in  one  direction ;  timber  thus 
injured  is  not  fit  for  squaring,  as  many  of  the  fibres  would  be  cut  through. 

The  large  trees  of  New  South  Wales,  when  at  full  maturity,  are  rarely  sound  at 
heart,  and  even  when  they  are  so,  the  immediate  heartwood  is  of  no  value,  on  account 
of  its  extreme  brittleness.  In  sawing  up  logs  into  scantlings  or  boards,  the  heart  is 
always  rejected.  The  direction  in  which  the  larger  species  split  most  freely  is  never 
from  the  bark  to  the  heart  (technically  speaking,  the  "  bursting  way  "),  but  in  concen- 


HIK 


219. 


trie  circles  round  the  latter.  Some  few  of  the  smaller  species  of  forest  trees  are  excep- 
tions to  this  rule ;  such  as  the  difierent  species  of  Casuarina,  Banhsia,  and  others 
belonging  to  the  natural  order  Proteacex.  They  split  most  freely  the  '■  bursting  way," 
as  do  the  oaks,  &c.,  of  Europe  and  America.  A  very  serious  defect  prevails  amongst  a 
portion  of  the  trees  of  this  class,  to  such  an  extent  as  to  demand  especial  notice  here.  It 
is  termed  "  gum-vein,"'  and  consists  simply  in  the  extravasation,  in  greater  or  less 
quantity,  of  the  gum-resin  of  the  tree,  in  particular  spots,  amongst  the  fibres  of  woody 
tissue,  and  probably  where  some  injury  has  been  sustained;  or,  which  is  a  much  greater 
evil,  in  concentric  circles  between  successive  layers  of  the  wood.  The  former  is  often  merely 
a  blemish,  affecting  the  appearance  rather  than  the  utility  of  the  timber ;  but  the  latter, 
when  occurring  frequently  in  the  same  section  of  the  trunk,  renders  it  comparatively 
worthless,  excepting  for  fuel.  In  the  latter  case,  as  the  wood  dries,  the  layers  with  gum 
veins  interposing  separate  from  each  other;  and  it  is  consequently  impracticable  to  take 
from  trees  so  afi'ected  a  sound  piece  of  timber,  excepting  of  very  small  dimensions.  The 
whole  of  the  species  of  Angophora,  or  apple-tree,  and  many  of  the  Eucalypti,  or  gums, 
aro  subject  to  be  thus  afi'ected ;  and  it  is  the  more  to  be  regretted,  because  it  appears  to 
be  the  only  reason  why  many  of  the  trees  so  blemished  should  not  be  classed  amongst 
the  most  useful  of  the  hard  woods  of  the  colony. 

In  selecting  balks  and  deals,  it  should  be  remembered  that  most  defects  show  better 
when  the  timber  is  wet.  Balk  timber  is  generally  specified  to  be  free  from  sap,  shakes, 
large  or  dead  knots  and  other  defects,  and  to  be  die-square.  The  best  American  yellow 
pine  and  crown  timber  from  the  Baltic  have  no  visible  imperfections  of  any  kind.  In 
the  lower  qualities  is  either  a  considerable  amount  of  sap,  or  the  knots  are  numerous, 
sometimes  very  large,  or  dead.  The  timber  may  also  be  shaken  at  heart  or  upon  the 
surface.  The  wood  may  be  waterlogged,  softened,  or  discoloured  by  being  floated. 
Wanes  also  are  likely  to  be  found,  which  spoil  the  sharp  angles  of  the  timber,  and 
reduce  its  value  for  many  purposes.  The  interior  of  the  timber  may  be  soft,  spongy,  or 
decayed,  the  surface  destroyed  by  worm  holes,  or  bruised.  The  heart  may  be  "  wan- 
dering"— that  is,  at  one  part  on  one  side  of  the  balk,  at  another  part  on  the  other  side. 
This  interrupts  the  continuity  of  the  fibre,  and  detracts  from  the  strength  of  the  balk. 
Again,  the  heart  may  be  twisted  throughout  the  length  of  the  tree.     In  this  case,  the 


Cakpentrt — Woods.  169 

annual  rings  which  run  parallel  to  2  sides  of  the  balk  at  one  end  rm  diagonally  across 
the  section  at  the  other  end.  This  is  a  great  defect,  as  the  wood  is  nearly  sure  to  twist 
in  seasoning.  Some  defects  appear  to  a  certain  degree  in  all  except  tlie  very  best  quality 
of  timber.  The  more  numerous  or  aggravated  they  are,  the  lower  is  the  quality  of  the 
timber.  Deals,  planks,  and  battens  should  be  carefully  examined  for  freedom  (more  or 
less  according  to  their  quality)  from  sap,  large  or  dead  knots,  and  other  defects,  also  to 
see  that  they  have  been  carefully  converted,  of  proper  and  even  thickness,  square  at  the 
angles,  &c.  As  a  rule,  well-converted  deals  are  from  good  timber,  for  it  does  not  pay  to 
put  much  labour  upon  inferior  material.  The  method  in  which  deals  have  been  cut 
should  be  noticed,  those  from  the  centre  of  a  log,  containing  the  pith,  should  be  avoided, 
as  they  are  likely  to  decay. 

Classification. — Timber  is  generally  divided  into  2  classes,  called  "  pine  "  woods  and 
"  hard  "  woods.  The  chief  practical  bearings  of  this  classification  are  as  follows : — Pine 
wood  (coniferous  timber)  in  most  cases  contains  turpentine ;  is  distinguished  by  straiglit- 
ness  of  fibre  and  regularity  in  the  figure  of  the  trees,  qualities  favourable  to  its  use  in 
carpentry,  especially  where  long  pieces  are  required  to  bear  either  a  direct  pull  or  a 
transverse  load,  or  for  purposes  of  planking ;  the  lateral  adhesion  of  the  fibres  is  small, 
so  that  it  is  much  more  easily  shora  and  split  along  the  grain  than  hard  wood,  and  is 
therefore  less  fitted  to  resist  thrust  or  shearing  stress,  or  any  kind  of  stress  that  does  not 
act  along  the  fibres.  In  hard  wood  (non-coniferous  timber)  is  no  turpentine  ;  the  degree 
of  distinctness  with  which  the  structure  is  seen  depends  upon  the  difference  of  texture 
of  several  parts  of  the  wood,  such  difterence  tending  to  produce  unequal  shrinking  in 
drying ;  consequently  those  kinds  of  timber  in  which  the  medullary  rays  and  the  annual 
rings  are  distinctly  marked  are  more  liable  to  warp  than  those  in  which  the  texture  is 
more  uniform  ;  but  the  former  kinds  are,  on  the  whole,  more  flexible,  and  in  many  cases 
very  tough  and  strong,  which  qualities  make  them  suitable  for  structures  that  have  to 
bear  shocks.  For  many  practical  purposes  timber  may  be  divided  into  two  classes : — 
(a)  soft  wood,  including  firs,  pines,  spruce,  larch,  and  all  cone-bearing  trees;  (h)  hard 
wood,  including  oak,  beech,  ash,  elm,  mahogany,  &c.  Carpenters  generally  give  the 
name  "  fir  "  to  all  red  and  yellow  timber  from  the  Baltic,  "  pine  "  to  similar  timber  from 
America,  and  "  spruce  "  to  all  white  wood  from  either  place. 

Market  Forms. — The  chief  forms  into  which  timber  is  converted  for  the  market  are 
as  follows : — A  "  log  "  is  the  trunk  of  a  tree  with  the  branches  lopped  off;  a  "  balk  "  is 
obtained  by  roughly  squaring  the  log.  Fir  timber  is  imported  in  the  subjoined  forms : 
"  Hand  masts  "  are  the  longest,  soundest,  and  straighteet  trees  after  being  topped  and 
barked ;  applied  to  those  of  a  circumference  between  24  and  72  in.,  measured  by  the 
hand  of  4  in.,  there  being  also  a  fixed  proportion  between  the  number  of  hands  in  tlio 
length  of  the  mast  and  those  contained  in  the  circumference  taken  at  i  the  length  from 
the  butt  end ;  "  spars  "  or  "  poles  "  have  a  circumference  of  less  than  24  in.  at  the  base ; 
"  inch  masts  "  have  a  circumference  of  more  than  72  in.,  and  are  generally  dressed  to  a 
square  or  octagonal  form  ;  "  balk  timber"  consists  of  the  trunk,  hewn  square,  generally 
with  the  axe  (sometimes  with  the  saw),  and  is  also  known  as  "  square  timber " ; 
"planks"  are  parallel-sided  pieces  2-6  in.  thick,  II  in.  broad,  and  8-21  ft.  long; 
"  deals  "  are  similar  pieces  9  in.  broad  and  not  exceeding  4  in.  thick  ;  "  whole  deals  "  is 
the  name  sometimes  given  to  deals  2  in.  or  more  thick ;  "  cut  deals  "  are  less  than  2  in. 
thick ;  "  battens  "  are  similar  to  deals,  but  only  7  in.  broad ;  " ends"  are  pieces  of  plank, 
deal,  or  batten  less  than  8  ft.  long;  "scaffold"  and  "  ladder  poles"  are  from  young  trees 
of  larch  or  spruce,  averaging  33  ft.  in  length,  and  classed  according  to  the  diameter  of 
their  butts ;  "  rickers  "  are  about  22  ft.  long,  and  under  2 J  in.  diameter  at  the  top  end ; 
smaller  sizes  are  called  "  spars."  Oak  is  supplied  as  follows  :  "  rough  timber  "  consists 
of  the  trunk  and  main  branches  roughly  hewn  to  octagonal  section ;  "  sided  timber," 
the  trunk  split  down  and  roughly  formed  to  a  polygonal  section  ;  "  thick  stuff,"  not  less 
than  24  ft.  and  averaging  at  least  28  ft.  long,  11-lS  in.  wide  between  the  sap  in  the  middle 


170  Caepentrt — Woods. 

of  its  length,  and  4J-S^  in.  tliick ;  "  planks,"  length  not  less  than  20  ft.  and  averaging 
at  least  28  ft.,  thickness  2—1  in.,  and  width  (clear  of  sap)  at  the  middle  of  the  length 
varying  according  to  the  thickness,  i.e.  between  9  and  15  in.  for  3-,  3J-,  and  4-in.  planks, 
between  8  and  15  in.  for  2-  and  2^-in.  planks.  "  Waney  "  timber  is  a  term  used  for  logs 
which  are  not  perfectly  square  ;  tlie  balk  cut  being  too  large  for  the  size  of  the  tree,  the 
square  corners  are  replaced  by  flattened  or  rounded  angles,  often  showing  the  bark,  and 
called  "  wanes."  "  Compass  "  timber  consists  of  bent  pieces,  the  height  of  the  bend 
from  a  straight  line  joining  the  ends  being  at  least  5  in.  in  a  length  of  12  ft. 

The  following  is  an  approximate  classification  of  timber  according  to  size,  as  knowa 
to  workmen : — 

Balk      12  in.  X  12  in.    to   18  in.  x  18  in. 

Whole  timber      ....        9       „       9         „      15       „     15   ,, 
Half  timber         .,      ..       9      „      4  J       „      18      „       9   „ 

Scantling      G       „       4         „      12       „     12   „ 

Quartering 2      „       2        „        6      „      6   „ 

Planks 11  in.  to  18  in.    x      3  in.   to   G   „ 

Deals 9  in.  x      2       „      U„ 

Battens         4Mn.  to  7  in.     x        ?     „      ^    „ 

Strips  and  laths  ..       2      „      4J         X        i     „       1|„ 

Pieces  larger  than  "  planks "  are  generally  called  "  timber,"  but,  when  sawn  all 
round,  are  called  "  scantling,"  and,  when  sawn  to  equal  dimensions  each  way,  "  die- 
square."  The  dimensions  (width  and  thickness)  of  parts  in  a  framing  are  sometimes 
called  the  "  scantlings  "  of  the  pieces.  The  term  "  deal  "  is  also  used  to  distinguish 
wood  in  the  state  ready  for  the  joiner,  from  "  timber,"  which  is  wood  prepared  for  the 
carpenter.     A  "  stick  "  is  a  rough  whole  timber  unsawn. 

Seasoning. — The  object  of  seasoning  timber  is  to  expel  or  dry  up  the  sap  remaining 
in  it,  which  otherwise  putrefies  and  causes  decay.  One  effect  is  to  reduce  the  weight. 
Tredgold  calls  timber  "seasoned"  when  it  has  lost  i,  and  considers  it  then  fit  for 
carpenters'  work  and  common  purposes ;  and  "  dry,"  fit  for  joiners'  work  and  framing, 
when  it  has  lost  i.  The  exact  loss  of  weight  depends,  however,  upon  the  nature  of  the 
timber  and  its  state  before  seasoning.  Timber  should  be  well  seasoned  before  being  cut 
into  scantlings ;  the  scantlings  should  then  be  further  seasoned,  and,  after  conversion, 
left  as  long  as  possible  to  complete  the  process  of  seasoning  before  being  painted  or 
varnished.  Logs  season  better  and  more  quickly  if  a  hole  is  bored  through  their  centre ; 
this  also  prevents  splitting. 

Natural  seasoning  is  carried  out  by  stacking  the  timber  in  such  a  way  that  the  air 
can  circulate  freely  round  each  piece,  at  the  same  time  protecting  it  by  a  roof  from  the 
sun,  rain,  draughts,  and  high  winds,  and  keeping  it  clear  of  the  ground  by  bearers.  The 
great  object  is  to  ensure  regular  drying ;  irregular  drying  causes  the  timber  to  split. 
Timber  should  be  stacked  in  a  yard,  paved  if  possible,  or  covered  with  ashes,  and  free 
from  vegetation.  The  bearers  should  be  damp-proof,  and  keep  the  timber  at  least  12  in. 
oiF  the  ground ;  they  should  be  laid  perfectly  level  and  out  of  winding,  otherwise  the 
timber  will  get  a  permanent  twist.  The  timber  should  bo  turned  frequently,  so  as  to 
ensure  equal  drying  all  round  the  balks.  When  a  permanent  shed  is  not  available, 
temporary  roofs  should  be  made  over  the  timber  stacks.  Logs  are  stacked  with  the  butts 
outwards,  the  inner  ends  being  slightly  raised  so  that  the  logs  may  be  easily  got  out ; 
packing  pieces  are  inserted  between  the  tiers  of  logs,  so  that  by  removing  them  any 
particular  log  may  be  withdrawn.  That  timber  seasons  better  when  stacked  on  end, 
seems  doubtful,  and  the  plan  is  practically  difficult  to  carry  out.  Boards  may  be  laid 
flat  and  separated  by  pieces  of  dry  wood  1  in.  or  so  in  thickness  and  3-4  in.  wide;  any 
that  are  inclined  to  warp  should  be  weighted  or  fixed  down  to  prevent  them  from 
twisting ;  they  are,  however,  frequently  stacked  vertically,  or  inclined  at  a  high  angle. 


Carpentry — Woods.  171 

Laslett  recommends  that  they  should  be  seasoned  in  a  dry  cool  shed,  fitted  with  horizontal 
beams  and  vertical  iron  bars,  to  prevent  the  boards,  -which  aro  placed  on  odo'e  from, 
tilting  over.  The  time  required  for  natural  seasoning  differs  with  the  size  of  the  pieces, 
the  nature  of  the  timber,  and  its  condition  before  seasoning.  Laslett  gives  the  follow- 
ing table  of  the  approximate  time  required  for  seasoning  timber  under  cover  and 
protected  from  wind  and  weather : — 

Oak.  Fir. 

Months.      Months. 

Pieces  24  in.  and  upward  square  require  about 26  13 

^      Under  24  in.  to  20  „  22  11 

„      20     „     IG  „  18  9 

«       16     „      12  „  14  7 

«       12     „       8  „  10  5 

«  >5  o      ^        4  y,  ••       ..       ..        b  o 

Planks  i-l  the  above  time,  according  to  thickness.  If  the  timber  is  kept  longer  than 
the  periods  above  named,  the  fine  shakes  which  show  upon  the  surface  in  seasoning  open 
deeper  and  wider,  until  they  possibly  render  the  logs  unfit  for  conversion.  The  time 
required  under  cover  is  only  f  of  that  required  in  the  open. 

Water  seasoning  consists  in  totally  immersing  the  timber,  chaining  it  down  under 
water,  as  soon  as  it  is  cut,  for  about  a  fortnight,  by  which  a  great  part  of  the  sap  is  washed 
out ;  it  is  then  carefully  dried,  with  free  access  of  air,  and  turned  daily.  Timber  thus 
seasoned  is  less  liable  to  warp  and  crack,  but  is  rendered  brittle  and  unfit  for  purposes 
where  strength  and  elasticity  are  required.  Care  must  be  taken  that  it  is  entirely  sub- 
merged; partial  immersion,  such  as  is  usual  in  timber  ponds,  injures  the  log  along  the 
water  line.  Timber  that  has  been  saturated  should  be  thoroughly  dried  before  use ; 
when  taken  from  a  pond,  cut  up  and  used  wet,  dry-rot  soon  sets  in.  Salt  water  makes 
the  wood  harder,  heavier,  and  more  durable,  but  should  not  be  applied  to  timber  for 
use  in  ordinary  buildings,  because  it  gives  a  permanent  tendency  to  attract  moisture. 

Boiling  water  quickens  the  operation  of  seasoning,  and  cai:ses  the  timber  to  shrink 
less,  but  it  is  expensive  to  use,  and  reduces  the  strength  and  elasticity.  The  time 
required  varies  with  the  size  and  density  of  the  timber,  and  according  to  circumstances ; 
one  rule  is  to  allow  1  hour  for  every  inch  in  thickness. 

Steaming  has  much  the  same  effect  as  boiling  ;  but  the  timber  is  said  to  dry  sooner, 
and  it  is  by  some  considered  that  steaming  prevents  dry-rot.  No  doubt  boiling  and 
steaming  partly  remove  the  ferment  spores. 

Hot-air  seasoning,  or  desiccation,  is  effected  by  exposing  the  timber  in  an  oven  to  a 
current  of  hot  air,  which  dries  up  the  sap.  This  process  takes  only  a  few  weeks, 
more  or  less,  according  to  the  size  of  the  timber.  "When  the  wood  is  green,  the  heat 
should  be  applied  gradually.  Great  care  must  be  taken  to  prevent  splitting  ;  the  heat 
must  not  be  too  high,  and  the  ends  should  bo  clamped.  Desiccation  is  useful  only  for 
small  scanthng ;  the  expense  of  applying  it  to  larger  timber  is  very  great ;  moreover,  as 
wood  is  one  of  the  worst  conductors  of  heat,  if  this  plan  be  applied  to  largo  logs,  the 
interior  fibres  still  retain  their  original  bulk,  while  those  near  the  surface  have  a  tendency 
to  shrink,  the  consequence  of  which  would  be  cracks  and  splits  of  more  or  less  depth. 
Desiccated  wood  should  not  be  exposed  to  damp  before  use.  During  this  process  ordinary 
woods  lose  their  strength,  and  coloured  woods  become  pale  and  wanting  in  lustre. 

M'Neile's  process  consists  in  exposing  the  wood  to  a  moderate  heat  in  a  moist  atmo- 
sphere charged  with  various  gases  produced  by  the  combustion  of  fuel.  The  wood  is  placed 
in  a  brick  chamber,  in  which  is  a  large  surface  of  water  to  produce  vapour.  The  timber  is 
stacked  in  the  usual  way,  with  free  air-space  round  every  piece ;  about  ^  of  the  whole  con- 
tent of  the  chamber  should  be  air-space.  Under  the  chamber  is  a  fireplace.  The  fire  having 
been  lighted,  the  products  of  combustion  (among  which  is  carbonic  acid  gas)  circulate 
freely  in  a  moist  state  around  the  pieces  of  timber  to  be  seasoned.     The  time  required 


172  Carpentry — Woods. 

varies  with  the  nature  of  the  -wood.  Oak,  ash,  mahogany,  and  other  hard  wood  planks 
3  in.  thick,  take  about  8  weeks ;  oak  wainscot  planks  2  in.  thick  take  5-6  weeks ;  deals 
3  in.  thick,  something  less  than  a  month;  flooring-boards  and  panelling,  about  10  days 
or  a  fortnight.  The  greener  the  wood  when  first  put  into  the  stove  the  better.  As  a 
rule,  if  too  great  heat  be  not  applied,  not  a  piece  of  sound  wood  is  split,  warped,  or  opened  iu 
any  way.  The  wood  is  rendered  harder,  denser,  and  tougher,  and  dry-rot  is  entirely  pre- 
vented. The  wood  will  not  absorb  by  subsequent  exposure  to  the  atmosphere  nearly  so 
much  moisture  as  does  wood  dried  by  exposure  in  the  ordinary  way.  Tlie  process  seems 
to  have  no  injurious  efl'ects  upon  the  appearance  or  strength  of  the  timber. 

Gardner's  jsrocess  is  said  to  season  timber  more  rapidly  tlian  any  other,  to  preserve 
it  from  decay  and  from  the  attacks  of  all  kinds  of  worms  and  insects,  to  strengthen 
the  timber,  and  render  it  uninflammable ;  and  by  it  the  timber  may  be  permanently 
coloured  to  a  variety  of  shades.  The  process  takes  4-14  days,  according  to  the  bulk  and 
density  of  the  timber.  It  consists  in  dissolving  the  sap  (by  chemicals  in  open  tanks), 
driving  out  the  remaining  moisture,  leaving  the  fibre  only.  A  further  injection  of 
chemical  substances  adds  to  the  durability,  or  will  make  the  timber  uninflammable. 
The  process  has  been  satisfactorily  tested  in  mine  props,  railway  sleepers,  logs  of 
mahogany  for  cabinet-work,  and  in  smaller  scantlings  of  fir  and  pine.  Experiments 
showed  that  the  sap  was  removed,  the  resistance  of  the  timber  to  crushing  augmented 
40-90  per  cent.,  and  its  density  considerably  increased. 

Rene',  a  pianoforte  manufacturer,  of  Stettin,  Germany,  has  devised  a  plan  by 
which  he  utilizes  the  property  of  ozonized  oxygen,  to  artificially  season  timber  used 
fur  sounding-boards  of  musical  instruments.  It  is  a  well-known  fact  that  wood,  which 
has  been  seasoned  for  years,  is  much  more  suitable  for  the  manufacture  of  musical 
instruments  than  if  used  soon  after  it  is  thoroughly  dried  only,  Rene  claims  that  instru- 
ments made  of  wood  which  has  been  treated  by  his  oxygen  process  possess  a  remarkably 
fine  tone,  which  not  only  does  not  decrease  with  age,  but  as  far  as  experience  teaches,  im- 
l)roves  with  age  as  does  the  tone  of  some  famous  old  violins  by  Italian  masters.  Sounding- 
boards  made  of  wood  prepared  in  this  manner  have  the  quality  of  retaining  the  sound 
longer  and  more  powerfully.  "While  other  methods  of  impregnating  woods  with  chemicals 
generally  have  a  deteriorating  influence  on  the  fibre,  timber  prepared  by  this  method, 
which  is  really  an  artificial  ageing,  becomes  harder  and  stronger.  The  process  is  regularly 
carried  on  at  Rene''s  works,  and  the  apparatus  consists  of  a  hermetically  closed  boiler 
■or  tank,  in  which  the  wood  to  be  treated  is  placed  on  iron  gratings ;  in  a  retort,  by 
the  side  of  the  boiler  and  connected  to  it  by  a  pipe  with  stop-valve,  oxygen  is  developed 
and  admitted  into  the  boiler  through  the  valve.  Provision  is  made  in  the  boiler  to 
ozonize  the  oxygen  by  means  of  an  electric  current,  and  the  boiler  is  then  gently  fired 
and  kept  hot  for  48-50  hours,  after  which  time  the  process  is  complete. 

Woods,  of  Cambridge,  Mass.,  has  introduced  a  method  which  is  spoken  of  as  leaving 
no  room  for  improvement.  The  wood  is  placed  in  a  tight  chamber  heated  by  steam,  and 
having  one  side  made  into  a  condenser  by  means  of  coils  of  pipes  with  cold  water  con- 
tinually circuluting  through  them.  The  surface  of  these  pipes  is  thus  kept  so  much  below 
the  temperature  of  the  chamber  that  the  moisture  drawn  from  the  wood  is  condensed 
on  them,  and  runs  thence  into  a  gutter  for  carrying  it  off.  In  the  words  of  the  United 
States  Report  on  the  Vienna  Exhibition,  "if  the  temperature  of  these  condensing  pipes 
can  be  kept  at  say  40°  F.,  and  that  of  the  atmosphere  be  raised  to  90°  F.,  it  will  not  require 
a  long  time  to  ruach  a  degree  of  20  per  cent,  of  saturation,  when  the  work  of  drying  is 
thoroughly  completed." 

Smoke-drying. — It  is  said  that  if  timber  be  smoke-dried  over  a  bonfire  of  furze, 
straw,  or  shavings,  it  will  be  rendered  harder,  more  durable,  and  proof  against  attacks 
of  worms ;  to  prevent  it  from  splitting,  and  to  ensure  the  moisture  drying  out  from  the 
interior,  the  heat  should  be  applied  gradually. 

Second  seasoning. — Many  -woods  require  a  second  seasoning  after  they  have  been 


Carpentry — Woods.  173 

worked.  Floor  boards  should,  if  possible,  be  laid  and  morcly  tnckod  down  for  several 
months  before  they  are  cramped  up  and  regularly  nailed.  Doora,  sashes,  and  other 
articles  of  joinery  should  be  left  as  long  as  possible  after  being  made,  before  they  are 
wedged  up  and  finished.  Very  often  a  board  that  seems  thoroughly  seasoned  will 
commence  to  warp  again  if  merely  a  shaving  is  planed  off  the  surface. 

Decay. — To  preserve  wood  from  decay  it  should  be  kept  constantly  dry  and  well 
ventilated;  clear  of  the  iuliuence  of  damp  earth  or  damp  walla,  and  free  from  contact 
with  mortar,  which  hastens  decomposition.  Wood  kept  constantly  submerged  is  often 
weakened  and  rendered  brittle,  but  some  timbers  are  very  durable  in  this  state.  Wood 
that  is  constantly  dry  is  very  durable,  but  also  becomes  brittle  in  time,  though  not  for 
a  great  number  of  years.  When  timber  is  exposed  to  alternate  moisture  and  dryness 
it  soonest  decays.  The  general  causes  of  decay  are  (1)  presence  of  sap,  (2)  exposure 
to  alternate  wet  and  dryness,  or  (3)  to  moisture  accompanied  by  heat  and  want  of 
ventilation. 

"  Eot "  in  timber  is  decomposition  or  putrefaction,  generally  occasioned  by  damp, 
and  which  proceeds  by  the  emission  of  gases,  chiefly  carbonic  acid  and  hydrogen ;  2  kinds 
of  rot  are  distinguished — "  dry  "  and  "  wet."  Their  chief  difference  seems  to  be  that 
wet-rot  occurs  where  the  gases  evolved  can  escape;  by  it,  the  tissues  of  the  wood, 
especially  the  sappy  portions,  are  decomposed.  Dry-rot,  on  the  contrary,  occurs  in 
confiued  places,  where  the  gases  cannot  get  away,  but  enter  into  new  combinations, 
forming  fungi  which  feed  upon  and  destroy  the  timber.  Wet-rot  may  take  place  while 
the  tree  is  standing ;  dry-rot  occurs  only  when  the  wood  is  dead. 

"Dry-rot"  is  generally  caused  by  want  of  ventilation;  confined  air,  without  much 
moisture,  encourages  the  growth  of  the  fungus,  which  cats  into  the  timber,  renders  it 
brittle,  and  so  reduces  the  cohesion  of  the  fibres  that  they  are  reduced  to  powder.  It 
generally  commences  in  the  sapwood.  Excess  of  moisture  prevents  the  growth  of  the 
fungus,  but  moderate  warmth,  combined  with  damp  and  want  of  air,  accelerates  it.  In 
the  first  stage  of  rottenness,  the  timber  swells  and  changes  colour,  is  often  covered  with 
fungus  or  mouldiness,  and  emits  a  musty  smell.  The  principal  parts  of  buildings  in 
which  it  is  found  are — warm  cellars,  under  unventilatcd  wooden  floors,  or  in  basements 
particularly  in  kitchens  or  rooms  where  there  are  constant  fires.  All  kinds  of  stoves 
increase  the  disease  if  moisture  be  present.  The  ends  of  timbers  built  into  walls  are 
nearly  sure  to  be  aflected  by  dry-rot,  unless  they  are  protected  by  iron  shoes,  lead,  or 
zinc.  The  same  result  is  produced  by  fixing  joinery  and  other  woodwork  to  walls  before 
they  are  dry.  Oilcloth,  kamptulicon,  and  other  impervious  floorcloths,  by  preventing 
access  of  air  and  retaining  dampness,  cause  decay  in  the  boards  they  cover  •  carpets  do 
the  same  to  a  certain  extent.  Painting  or  tarring  cut  or  unseasoned  timber  has  a  like 
effect. 

Sometimes  the  roots  of  large  trees  near  a  house  penetrate  below  the  floors  and  cause 
dry-rot.  It  is  said  that  if  two  kinds  of  wood — as,  for  example,  oak  and  fir— are  placed 
so  as  to  touch  end  to  end,  the  harder  will  decay  at  the  point  of  junction.  There  is  this 
particular  danger  about  dry-rot,  that  the  germs  of  the  fungi  producing  it  are  carried 
easily,  and  in  all  directions,  in  a  building  where  it  once  displays  itself,  without  necessity 
for  actual  contact  between  the  affected  and  the  sound  wood. 

"  Wet-rot "  occurs  in  the  growing  tree,  and  in  other  positions  where  the  timber  may 
become  saturated  with  rain.  If  the  wood  can  be  thoroughly  dried  by  seasoning,  and 
the  access  of  further  moisture  can  be  prevented  by  painting  or  sheltering,  wet-rot  can 
bo  prevented.  The  communication  of  the  disease  only  takes  place  by  actual  contact. 
To  detect  dry-rot,  in  the  absence  of  any  outward  fungus,  or  other  sign,  the  best  way  is 
to  bore  into  the  timber  with  a  gimlet  or  auger.  A  log  apparently  sound,  as  far  as 
external  appearances  go,  may  be  full  of  dry-rot  inside,  which  can  be  detected  by  the 
appearance  of  the  dust  extracted  by  the  gimlet,  or  more  especially  by  its  smell.  If  a 
piece  of  sound  timber  be  lightly  struck  with  a  key  or  scratched  at  one  end,  the  sountl 


174  Carpentry — Woods. 

can  be  distinctly  heard  by  a  person  placing  his  ear  against  the  other  end,  even  if  the 
balk  be  50  ft.  long  ;  but  if  the  timber  be  decayed,  the  sound  will  be  very  faint,  or  alto- 
gether prevented  from  passing  along.  Imported  timber,  especially  fir,  is  often  found  to 
be  suffering  from  incipient  dry-rot  upon  arrival.  This  may  have  originated  in  the  wood 
of  the  ship  itself,  or  from  the  timber  having  been  improperly  stacked,  or  shipped  in  a 
wet  state,  or  subjected  to  stagnant,  moist,  warm  air  during  the  voyage.  Sometimes 
the  rot  appears  only  in  the  form  of  reddish  spots,  which,  upon  being  scratched, 
.show  that  the  fibres  have  been  reduced  to  powder.  After  a  long  voyage,  however, 
the  timber  will  often  be  covered  with  white  fibres  of  fungus.  Canadian  yellow  pine 
is  very  often  found  in  this  state.  The  best  way  of  checking  the  evil  is  to  sweep  the 
fungus  off,  and  rcstack  the  timber  in  such  a  way  that  the  air  can  circulate  freely  round 
each  piece. 

Preserving. — The  best  means  for  preserving  timber  from  decay  are  to  have  it 
thoroughly  seasoned  and  well  ventilated.  Painting  preserves  it  if  the  wood  is  thoroughly 
seasoned  before  the  paint  is  applied ;  otherwise,  filling  up  the  outer  pores  only  confines 
the  moisture  and  causes  rot.  The  same  may  be  said  of  tarring.  Sometimes  before 
the  paint  is  dry  it  is  sprinkled  with  sand,  which  is  said  to  make  it  more  durable.  For 
timber  tliat  is  not  exposed  to  the  weather,  the  utility  of  paint  is  somewhat  doubtful. 
"Wood  used  in  outdoor  work  should  have  those  parts  painted  only  where  moisture  is 
likely  to  find  a  lodgment,  and  all  shakes,  cracks,  and  joints  should  be  filled  up  with 
white-lead  ground  in  oil,  or  oil  putty,  previous  to  being  painted  over.  The  lower  ends 
of  posts  put  into  the  ground  are  generally  charred  with  a  view  of  preventing  dry-rot 
and  tlie  attacks  of  worms.  Care  should  be  taken  that  the  timber  is  thoroughly  seasoned, 
otherwise,  by  confining  the  moisture,  it  will  induce  decay  and  do  more  harm  than  good. 
Posts  should  be  put  in  upside  down,  with  regard  to  the  position  in  which  they  originally 
grew ;  the  sap  valves  open  upwards  from  the  root,  and  when  thus  reversed  they  prevent 
the  ascent  of  moisture  in  the  wood.  Britten  recommends  charring  the  embedded  portions 
of  beams  and  joists,  joists  of  stables,  wash-houses,  &c.,  wainscoting  of  ground-floors, 
flooring  beneath  pan^uet  work,  joints  of  tongues  and  rebates,  and  railway  sleepers. 
Lapparent  applied  the  method  on  a  large  scale  by  the  use  of  a  gas  jet  passed  all  over 
the  surface  of  the  timber,  but  Laslett  would  only  advise  its  use  as  a  possible  means  of 
preventing  the  generation  of  moisture  or  fungus  where  two  unseasoned  pieces  of  wood 
are  placed  in  juxtaposition. 

There  are  some  preserving  processes  of  a  special  character,  not  available  for  applica- 
tion by  the  carpenter.  These  are  described  at  length  in  the  Second  Series  of  '  Workshop 
Receipts,'  under  the  head  of  Preserving  "Wood,  pp.  45G-468.  A  few  simpler  methods 
may  be  mentioned  here.  The  following  will  be  found  a  good  method  of  preserving 
wooden  posts,  say  verandah  posts,  from  decay,  and  also  from  the  white  ant,  which  is  the 
greatest  enemy  to  carpenters'  work  in  Ceylon.  Bore  with  a  IJ-in.  auger  from  the  butt- 
end  of  the  post  to  a  distance  that  will  be  G  in.  above  the  ground-line  when  the  post  is 
set.  Then  char  over  a  good  fire  for  15  minutes.  This  will  drive  all  moisture  out  of  the 
heart  of  the  butt  through  the  hole  bored.  Next  fill  with  boiling  hot  coal-tar,  and  drive 
in  a  well-fitted  plug,  which  will  act  as  a  ram,  and  force  the  tar  into  the  pores  of  the 
wood  ;  the  latter  thus  becomes  thoroughly  creosoted,  and  will  last  for  many  years.  A 
post  4  in.  X  4  in.  may  have  one  hole  in  its  centre  ;  a  post  G  in.  x  6  in.,  2  holes  side  by 
side;  a  iwst  8  in.  x  8  in.,  3  holes;  and  one  12  in.  x  12  in.,  4  holes.  Creosoting  timber 
for  sleepers  and  iinderground  purposes  answers  very  well;  also  coal-tar  is  a  great 
means  of  preserving  timber  underground  from  the  efiects  of  the  white  ant,  as  they 
will  not  touch  it  as  long  as  there  is  a  smell  of  tar  from  it.  A  method  used  by  the 
natives  to  protect  timber  from  white  ants  is — To  every  gallon  of  water  add  3  oz. 
croton  tiglium  seeds,  3  oz.  margosa  bark,  3  oz.  sulphur,  2  oz.  blue  vitriol ;  immerse  the 
timber  until  it  ceases  to  absorb  the  water,  and  afterwards  take  out,  and  dry  in  an  airy 
situation. 


CARrENTEY — Woods. 


175 


The  following  table  shows  the  amount  of  creosote  that  will  be  taken  up  by  some  of 
the  harder  Indian  woods : — 


Lb.  of 
Creosote  per 
cub.  ft. 

Sissil       33 

Sundri 2i 

Teak        1? 

Swau  Eiver  wood  (Australia)  1^ 


Sal     ..      .. 
Iron  wood  ., 
Mahogany 
Jaman 


:l.b.  of 

Creosote  per 

cub.  ft. 

..      1 

..      1 


It  was  thought  that  the  forests  of  Southern  India  would  furnish  numerous  timbers 
suitable  for  sleepers  ;  but  these  hopes  have  not  been  fulfilled,  no  timber  used  having 
been  found  capable  of  resisting  the  combined  effects  of  the  heat  and  moisture  of  Southern 
India,  and  only  on  the  woods  of  3  trees  is  any  great  reliance  now  placed,  viz.  the  Erool 
(^Liga  xylocarjM),  Karra  marda  (Terminalia  glabra),  and  Vengay  {Pterocarpus  Marsu- 
pium).  Taking  an  average  of  the  various  native  woods  used  on  the  Madras  railway, 
the  duration  of  its  sleepers  has  been  about  oh  years.  Creosoted  sleepers  of  Baltic  fir 
have  been  found  to  last  nearly  6J  years. 

Fireproofing. — The  accepted  methods  for  rendering  wood  incombustible  or  reducing 
its  inflammability  are  described  in  the  Second  Series  of  'Workshop  Receipts,'  under 
the  head  of  Fireproofing  Timber,  pp.  298-9. 

Conversion;  Shrinhage. — By  the  term  "  conversion"  is  understood  the  cutting  up  of 
the  log  or  balk  timber  to  dimensions  suitable  for  use,  allowance  being  made  for  alterations 
in  form  due  to  atmospheric  influence,  even  on  well-seasoned  wood.  While  wood  is  iu 
the  living  state,  a  constant  passage  of  sap  keeps  the  whole  interior  moist  and  the  fibres 
distended,  more  especially  towards  the  outsido.  When  the  tree  is  felled  and  exposed 
to  the  air,  the  internal  moisture  evajwrates  gradually,  causing  a  shrinkage  and  collapse 
of  the  fibres  according  to  certain  laws,  being  always  greatest  in  a  direction  parallel  with 
the  medullary  rays.  In  straight-grained  woods  the  changes  of  length  caused  by 
atmospheric  effects  are  slight,  but  those  in  width  and  depth  are  great,  especially  in  new 
timber.  Ordinary  alternations  of  weather  produce  expansion  and  contraction  iu  width 
in^wood  of  average  dryness  to  the  following  extent : — fir :  -^^  to  Jj,  mean  -^^^  ;  oak : 
_i^  to  ^'jf,  mean  -^.  A  practical  allowance  for  shrinkage  in  9-in.  deals  is  J  in.  for 
northern  pine  and  \  in.  for  white. 

The  subject  of  shrinkage  in  timber  has  been  well  dealt  with  by  Dr.  Anderson,  in  a 
Cantor  Lecture  at  the  Society  of  Arts.  His  observations  may  be  summarized  as  follows. 
If  Fig.  220  be  taken  as  representing  the  section  of  a  newly-felled  tree,  it  will  be  seen 
that  the  wood  is  solid  throughout,  and  on  comparing  Fig.  221>ith  this  the  result  of  the 
seasoning  will  be  apparent.  The  action  is  exaggerated  in  the  diagrams  in  order  to 
render  it  more  conspicuous.  As  the  moisture  evaporates,  the  bundles  of  woody  fibres 
shrink  and  draw  closer  together  ;  but  this  contraction  cannot  take  place  radially,  without 
crushing  or  tearing  the  hard  plates  forming  the  medullary  rays,  which  are  unafl"ccted 
in  size  by  the  seasoning.  These  plates  are  generally  sufficiently  strong  to  resist  tlie 
crushing  action,  and  the  contraction  is  therefore  compelled  to  take  place  in  the  opposite 
direction,  i.e.  circumferentially ;  the  strain  finding  relief  by  si^litting  the  timber  in 
radial  lines,  allowing  the  medullary  rays  in  each  partially  severed  portion  to  approach 
each  other  in  the  same  direction  as  tlio  ribs  of  a  lady's  fan  when  closing.  The  illustra- 
tion of  a  closing  fan  afi"ords  the  best  example  of  the  principle  of  shrinking  during 
seasoning,  every  portion  of  the  wood  practically  retaining  its  original  distance  from  the 
centre.  If  the  tree  were  sawn  down  the  middle,  the  cut  surfaces,  although  flat  at  first, 
would  in  time  become  rounded,  as  in  Fig.  222 ;  the  outer  portion  shrinking  more  than 
that  nearer  the  heart  on  account  of  the  greater  mass  of  woody  fibre  it  contains,  and  the 
larger  amount  of  moisture.    If  cut  into  quarters,  each  portion  would  present  a  similar 


176 


Carpentry — "Woods. 


resnlt,  as  shown  in  Fig.  223.  Figs.  224-228  show  the  same  principle  applied  to  sawn 
timber  of  various  forms,  the  peculiarities  of  which  are  perhaps  indicated  more  clearly  in 
Fig.  230.  If  we  assume  the  tree  to  be  cut  into  planks,  as  shown  in  Fig.  229,  it  will  be 
found,  after  allowing  due  time  for  seasoning,  that  the  planks  have  altered  their  shape, 
as  in  Fig.  230.     Taking  the  centre  plank  first,  it  wUl  be  observed  that  the  thickness  at 


220. 


221. 


222. 


the  middle  remains  unaltered,  at  the  edge  it  is  reduced,  and  both  sides  are  rounded, 
while  the  width  remains  unchanged.  The  planks  on  each  side  of  this  are  rounded  on 
the  heart  side,  hollow  on  the  other,  retain  their  middle  thickness,  but  are  reduced 
in  width  in  proportion  to  their  distance  from  the  centre  of  the  tree ;  or,  in  other  words^ 


223. 


224. 


225. 


the  more  nearly  the  annual  rings  are  parallel  to  the  sides  of  the  planks  the  greater  will 
be  the  reduction  in  width.  The  most  striking  result  of  the  shrinkage  is  shown  in 
Figs.  231-233.  Fig.  231  shows  a  piece  of  quartering  freshly  cut  from  unseasoned  timber  ; 
in  Fig.  232  the  part  coloured  black  shows  the  portion  lost  by  shrinkage,  and  Fig.  233 


226. 


227. 


223. 


shows  the  final  result.  These  remarks  apply  more  especially  to  oak,  beech,  and  the 
stronger  home  firs.  In  the  softer  woods  the  medullary  rays  are  more  yielding,  and  this 
slightly  modifies  the  result ;  but  the  same  principles  must  be  borne  in  mind  if  we  wish 
to  avoid  the  evils  of  shrinking  which  may  occur  from  negligence  in  this  respect. 


Carpentry— Woods. 


177 


The  peculiar  dii-ection  which  "  shakes  "  or  natural  fractures  sometimes  take  is  due  to 
the  unequal  adhesion  of  the  woody  fibres,  the  weakest  part  yieldinjj;  first.  In  a"  cup-thake," 
which  is  the  separation  of  a  portion  of  2  annual  rings,  the  medullary  rays  arc  deficient 
in  cohesion.  The  fault  sometimes  occurs  in  Dantzic  fir,  and  has  been  attributed  to  the 
action  of  lightning  and  of  severe  frosts.  So  far  we  have  considered  the  shrinking  only 
as  regards  tiie  cross  section  of  various  pieces.  Turning  now  to  the  effect  produced 
when  we  look  at  the  timber  in  the  other  direction,  Fig.  2oi  represents  a  piece  of  timber 
with  the  end  cut  off  square;  as  this  shrinks,  the  end  remains  square,  the  width  alone 
being  affected.    If,  ho\Yever,  the  end  be  bevelled  as  iu  Fig.  235,  we  shall  find  that  in 


229. 


230. 


231. 


A 


\J 


K 


v 


'\i\y 


shrinking  it  assumes  a  more  acute  angle,  and  this  should  be  remembered  in  framing 
roofs,  arranging  the  joints  for  struts,  &c. ,  especially  by  the  carpenters  who  have  to  do 
the  actual  work  of  fitting  the  parts.  If  the  angle  be  an  internal  one  or  bird's-mouth,  it 
will  in  the  same  way  become  more  acute  in  seasoning.  The  transverse  shrinkage  is 
here  considered  to  the  exclusion  of  any  slight  longitudinal  alteration  which  might 
occur,  and  which  would  never  be  sufficient  to  affect  the  angle  of  the  bevel.  When 
seasoned  timber  is  used  in  positions  subject  to  damp,  the  wood  will  swell  in  exactly  the 


232. 


233. 


234. 


reverse  direction  to  the  shrinkage,  and  induce  similar  difficulties  unless  this  point  has 
also  received  due  attention.  Of  course  it  will  be  seen  from  a  study  of  the  cross 
sections  illustrated  in  the  diagrams  that  the  pieces  might  be  selected  iu  such  a  way  that 
the  shrinkage  and  expansion  would  take  place  chiefly  in  the  thickness  instead  of  the 
width,  and  thus  leave  the  bevel  unaltered.  In  this  consists  the  chief  art  of  selecting 
pieces  for  framing  ;  but  in  many  instances  motives  of  economy  unfortunately  favour  the 
use  of  pieces  on  stock,  without  reference  to  their  suitability  for  the  purpose  required. 

It  has  been  proved  tliat  beams  having  the  annual  rings  parallel  witli  their  deptl:  are 
stronger  than  those  having  them  parallel  with  their  breadth.    Thus  in  the  log  shown  in 

N 


178 


Cakpente  Y —  Woods. 


Fig.  236,  the  beam  cut  from  A  -u-ill  be  stronger  than  that  from  B.  In  preparing  floor- 
boards, care  should  be  taken  that  the  heart  does  not  appear  on  the  surface  of  the 
finished  board,  or  it  -will  soon  become  loose  and  kick  up,  as  in  Fig.  237,  forming  a 
rough  and  unpleasant  floor.  When  planks  which  have  curved  in  shrinking  are  needed 
to  form  a  flat  surface,  they  are  sometimes  sawn  down  the  middle,  and  tiie  pieces  are 
alternately  reversed  and  glued  together,  as  in  Fig.  238,  each  piece  tending  to  check  the 
curvature  of  the  others. 

In  converting  fir  timber  in  Sweden  and  Norway,  each  log  is  inspected  before  sawing, 
to  see  how  many  of  the  most  marketable  sizes  it  will  cut,  and  then  it  is  marked  out 
accordingly.    The  most  general  arrangement  is  that  shown  in  Fig.  239,  the  thicker  deals 


236 


237. 


238. 


being  for  the  English  and  the  thinner  for  the  Frcncli  market.  Another  plan,  shown  in 
Fig.  240,  has  the  disadvantage  that  the  central  deal  embraces  all  the  pith,  and  is  thus 
rendered  more  liable  to  dry-rot. 

In  converting  oak,  the  log  is  first  cut  into  4  quarters,  each  of  which  may  then  be 
dealt  with  as  shown  in  Fig.  241.  The  best  method  is  represented  at  a;  it  gives  no 
waste,  as  the  triangular  portions  form  feather-edged  laths  for  tiling,  &c.;  it  also  shows 
the  silver  grain  of  the  wood  to  the  best  advantage,  b  is  the  next  in  order  of  merit ; 
c  is  inferior ;  d  is  most  economical  for  thick  stufi". 

Comimsition. — The  composition  of  wood  is  shown  in  the  following  table  : — 


Carbon. 

Hydrogen. 

Oxygen. 

Nitrogen. 

Ash. 

Beech      

Oak 

Biroh        

Poplar      

Willow     

per  cent. 
49-36 
49-64 
50-20 
49-37 
49-96 

per  cent. 
6-01 
5-02 
6-20 
6-21 
5-96 

per  cent. 

42-69 

41  •  IG 

41-62 

41-60 

39-56 

per  cent. 
0-91 
1-29 
1-15 
0-96 
0-96 

per  cent. 
100 
1-97, 
0-81  ^ 
1-86  ' 
3-37    ■ 

Average     . . 
Practically 

49-70 
50 

6-06 
6 

41-30 
41 

1-05 
1 

1-80 

2    ■' 

CAErENTRY — Woods. 


179 


Wood,  in  its  raw  state,  contains  a  largo  amount  of  water,  which  holds  more  or  less 
soluble  minerals,  and  is  called  sap.  By  drying  wood  a  great  ])art,  but  not  all,  of  this 
water  is  evaporated.  If  wood  is  dried  in  a  closed  vessel,  and  then  exposed  to  tlic  atmo- 
sphere, it  quickly  absorbs  moisture  ;  biit  the  moisture  thus  absorbed  is  much  less  than  the 
wood  originally  contained.  The  amount  of  water  varies  in  diflercnt  kinds  of  wood,  and 
according  to  the  season.  Wood  cut  in  April  contains  10-20  per  cent,  more  water  than 
tliat  cut  in  January.  The  following  table  shows  the  percentage  of  water  in  woods,  dried 
as  far  as  possible  in  the  air  : — 


Beech       18-6 

Poplar      2G-0 

Sugar  and  common  maple  27*0 

Ash 28-0 

Birch 30-0 

Oak,  red 34-7 

Oak,  white       35-5 


Pine,  white      37-0 

Chestnut  .,      38-2 

Pine,  red 39-7 

Pine,  white      45  •  5 

Linden     47-1 

Poplar,  Italian        , .      . .  48-2 

Poplar,  black 51  •  8 


Wood  cut  during  December  and  January  is  not  only  more  solid,  but  will  dry  faster 
than  at  any  other  period  of  the  year,  because  the  sap  by  that  time  has  incorporated  a 
great  part  of  soluble  matter  with  the  woody  fibre ;  what  remains  is  merely  water.  When 
the  sap,  during  February,  March,  and  April,  rises,  it  partly  dissolves  the  woody  fibre, 
and  the  drying  of  the  wood  is  not  only  retarded,  but  the  wood  is  weakened  in  consequence 
of  the  matter  thus  held  in  solution. 

Suitability. — The  properties  which  render  a  wood  most  suitable  for  one  class  of 
purposes  may  preclude  its  use  in  another  class.  It  is  therefore  useful  to  have  a 
general  idea  of  the  relative  order  of  merit  of  woods  according  to  the  application  for  which 
they  are  destined.  The  subjoined  catalogue  is  framed  after  the  ojjinions  of  the  best 
authorities : — 

Elasticity — ash,  hickory,  hazel,  lancewood,  chestnut  (small),  yew,  snakewood. 

Elasticity  and  Toughness — oak,  beech,  elm,  lignum-vita3,  walnut,  hornbeam. 

Even  grain  (for  Carving  or  Engraving) — pear,  pine,  box,  lime  tree. 

Durability  (in  Dry  Works) — cedar,  oak,  yellow  pine,  chestnut. 

Building  (Ship-building)^ — cedar,  pine  (deal),  fir,  larch,  elm,  oak,  locust,  teak. 

Wet  construction  (as  piles,  foundations,  flumes,  &c.) — elm,  alder,  beech,  oak,  white- 
wood,  chestnut,  ash,  spruce,  sycamore. 

Machinery  and  mill  work  (Frames) — ash,  beech,  birch,  pine,  elm,  oak. 

Hollers,  &c. — box,  lignum-vitie,  mahogany. 

Teeth  of  wheels — crab  tree,  hornbeam,  locust. 

Foundry  patterns — alder,  pine,  mahogany. 

Furniture  (Common) — beech,  birch,  cedar,  cherry,  pine,  whitewood. 

Best  furniture — amboyna,  black  ebony,  mahogany,  cherry,  maple,  walnut,  oak, 
rosewood,  satinwood,  sandalwood,  chestnut,  cedar,  tulip-wood,  zebra-wood,  ebony. 

Piles — oak,  beech,  elm.  Posts — chestnut,  acacia,  larch.  Great  Strength  in  Con- 
struction— teak,  oak,  greenheart,  Dantzic  fir,  pitch  pine.  Durable  in  Wet  Positions — 
Ofik,  beech,  elm,  teak,  alder,  plane,  acacia,  greenheart.  Large  Timbers  in  Carpentry — 
Memel,  Dantzic,  and  Riga  fir;  oak,  chestnut,  Bay  mahogany,  pitch  pine,  or  teak,  may  be 
used  if  easily  obtainable.  Floors — Christiania,  St.  Petersburg,  Onega,  Archangel,  make 
the  best;  Gefle  and  spruce  inferior  kinds  ;  Dram  battens  wear  well ;  pitch  pine,  oak,  or 
teak,  where  readily  procurable,  for  floors  to  withstand  great  wear.  Panelling — American 
yellowpiuefor  the  best ;  Christiania  white  deals  are  also  used.  Interior  Joinery — American 
red  and  yellow  pine ;  oak,  pitch  pine,  and  mahogany  for  superior  or  ornamental  work. 
Window  Sills,  Sleepers — oak  ;  mahogany  where  cheaply  procurable.  Treads  of  Stairs — 
oak,  teak.    Handles— ash,  beech.    Patterns — American  yellow  pine,  alder,  mahogany. 

N  2 


180  Carpentry — "Woods. 

Strength. — The  following  table  shows  the  results  of  many  cxpeiiments  ; 


Wood  seasoned. 


Weight  of 

1  cub.  ft. 

(dry.) 


Acacia 

Alder 

Ash,  English    .. 

„     Canadian   . . 

Beech 

Bh-ch 

Cedar  

Chestnut    . . 
Elm,  English    .. 

„     Canadian . . 
Fir,  Spruce 

„  Dantzic 

„  American  red 
pine 

„  American  yel- 
low pine . . 

„  Memel . . 

,,  Kuurie 

„  Pitch  pine  .. 

„  Riga    ..      .. 
Greenheart 
Hornbeam . . 
Jarrali 

Larch 

Mahogany, 

Spanish 
„      Honduras 

Mora 

Oak,  English     .. 

„     American.. 

Plane 

Poplar 
Sycamore  .. 

Teak 

Willow       ..      .. 


Lb. 


48 

50 
43-53 

30 
43-53 
45-49 
35-47 
35-41 
34-37 

47 
29-32 

3G 


32 

34 

34 
41-58 
34-47 
58-72 
47-5 

63 
32-38 

53 

35 
57-68 
49-58 

Gl 

40 
23-26 
36-43 
41-52 
24-35 


Tenacity 
poTfq.  in., 
length- 
ways of 
the  grain. 


Tons. 


From.  To. 


0  8'1 
5  6-3 
8  7-6 
45 

1  6-6 
7 

3  5-1 
5  5-8 

4  6-3 
1 

3 
4 


4-5 
4-5 


2  6-0 

9 

2  4-9 

0 

1  4-4 

8  5-5 

9  4-1 
1 

3 

9  5-3 


7  7-3 

3  8-4 
1 

4  8-8 
0  4-6 
4 

68 

3  5-8 
47  6-7 


Modulus 

of 
Rupture. 


1000  lb. 


6-25 


12-14 

10 
9-12 

11 
7-8 

10 
6-9 

14 
9-12 

13 

7-10 


11 
14 

9 
16-27 

10 
5-10 

7 
11-12 
21-22 
10-13 

12 


9 

12-19 

6 


l\Iodulu8 

of 

Elasticity. 


1000  lb. 


1152-1687 

1086 
1525-2290 

1380 

1350 

1645 
486 

1140 
700-1340 

2470 
1400-1800 

2300 

1460-2350 

1600-2480 
153G-1957 

2880 
1252-3000 
870-3000 

1700 

1187 
1360 

1255-3000 
1596-1970 

18G0 
1200-1750 

2100 

1343 
763 

1040 
2167-2414 


Resistance 
to  Crush- 
ing in 
direction 
of  fibres. 


Tons  per 
sq.  in. 

■e    .      1^  ■ 


H 

•8  4-2 
2-5 
4  4-2 
•5  2-8 
■5  2-6 


2-6  4«6 
4-1 

2-9  3-0 
31 

2-1 

1-8 
6 

2-6 
3-0 
2-1 
5-8  6-8 
3-7 
3-2 
2-6 

3-2 

2-7 

2-9""4-5 
31 

l-4"2-3 

3-1 

2-3  5-4 

1-3  2-7 


Comparative 

Stiffness  and 

Strength,  Oak 

being  100. 


Stiff- 
ness. 


98 
63 
89 

77 
77 

28 
67 
78 

139 
72 

130 

132 

139 

114 

162 

73 

62 

98 

67 
79 

73 
93 

105 
100 
114 

78 

44 

82 

126 


Strength. 


95 
80 

119 
79 

103 

62 
89 
82 

114 
86 

108 

81 

66 

80 

89 

82 

83 

165 

108 

85 

103 

67 

96 

164 

100 

86 

92 

50 

111 

109 


Timber  when  wet  has  not  half  the  strcngtli  of  the  same  when  dry.  The  resistance 
of  wood  to  a  crushing  force  exerted  across  the  fibres  is  much  less  than  in  the  direction  of 
their  length.  Memel  fir  is  indented  with  a  pressure  of  1000  lb.  per  sq.  in.,  and  oak  with 
1400  lb.  The  resistance  to  shearing  is  nearly  twice  as  great  across  the  fibres  as  with 
them. 

Measuring. — Following  are  useful  rules  for  the  measurement  of  timber: — 
Standing  timber. — In  measuring  standing  limber,  the  length  is  talcen  as  high  as  the 
tree  will  measure  24  in.  in  circumference.  At  half  this  height  the  measurement  for 
the  mean  girth  of  the  timber  in  the  stem  of  the  tree  is  taken.  One-fourth  this  girth  is 
assumed  to  be  the  side  of  the  equivalent  square  area.  The  buyer  has  generally  the 
option  of  choosing  any  spot  between  the  butt-end  and  the  half  height  of  the  stem  as  the 


Carpentry — "Woods.  181 

girding  jilace.  All  branches,  as  far  as  they  measure  24  in.  in  girth,  are  measured  in 
with  the  tree  as  timber. 

Uiisquarod  timber. — In  order  to  ascertain  the  contents,  multiply  the  square  of  the 
quarter  giith,  or  of  J  of  the  mean  circumference,  by  tlie  length.  Wlien  the  buyer  ia 
not  allowed  his  choice  of  girth  in  taper  trees,  he  may  take  the  moan  dimensions,  either 
by  girthing  it  in  the  middle  for  the  mean  girth,  or  by  girthing  it  at  tiie  two  ends,  and 
taking  half  of  their  sum.  If  not,  girtli  the  tree  in  so  many  places  as  is  thought  necessary, 
then  the  sum  of  the  several  girths  divided  by  their  number,  will  give  a  mean  circumfer- 
ence, the  foiuth  part  of  which  being  squared,  and  multiplied  by  the  length,  will  give  the 
solid  contents. 

The  sviperficial  ft.  in  a  board  or  plank  are  known  by  multiplying  the  length  by  the 
breadth.  If  the  board  be  tapering,  add  the  breadth  of  the  two  ends  together,  and  take 
half  their  sum  for  the  mean  breadth,  and  multiply  the  length  by  this  mean  breadth. 

The  solid  contents  of  squared  timber  are  found  by  measuring  the  mean  brendth  by 
the  mean  thickness,  and  the  product  again  by  the  length.  Or  multiply  tlie  square  of  what 
is  called  the  quarter  girth,  in  inches  by  the  length  in  feet,  and  divide  by  141,  and  you  have 
the  contents  in  feet. 

Boughs,  the  quarter  girth  of  which  is  less  than  6  in.,  and  jmrts  of  the  trunk  less  than 
2  ft.  in  circumference,  are  not  reckoned  as  timber. 

1^  in.  in  every  foot  of  quarter  girth,  or  I  of  the  girth,  is  allowetl  for  bark,  except  of 
elm.  1  in.  in  the  circumference  of  the  tree,  or  whole  girth,  or  -jV  of  the  quarter  girth  is 
the  general  fair  average  allowance. 

Tlie  quarter  girth  is  half  the  sum  of  the  breadth  and  depth  in  the  middle. 

The  nearest  approach  to  truth  in  the  measuring  of  timber  is  to  multiply  the  square 
of  i  of  the  girth,  or  circumference,  by  double  the  length,  and  the  product  will  be  the 
contents. 

100  superficial  feet  of  planking  equals  1  square. 

120  deals  „       l  hundred. 

50  cub.  ft.  of  squared  timber  „       1  load. 

40  ft.  of  unhewn  timber  „       1  load. 

600  superiicial  ft.  of  1-in.  planking  „         1  load. 

A  fir  pole  is  the  trunk  of  a  fir  tree,  10-lG  ft.  long. 

Battens,  deals,  and  planks,  as  imported  into  this  country,  are  each  similar  in  their 
various  lengths,  but  differing  in  their  widths  and  thicknestes,  and  hence  their  principal 
distinction  ;  thus,  a  batten  is  7  in.  liy  2J  in. 
a  deal      ,,9      „     3     „ 
a  plank  „  11      „      3     „ 

these  being  what  are  termed  the  standard  dimensions,  by  which  they  are  bought  and  sold, 
the  length  of  each  being  taken  at  12  ft. ;  therefore,  in  estimating  for  the  proper  value  of 
any  quantity,  nothing  more  is  required  than  their  lineal  dimensions  by  weich  to 
ascertain  the  number  of  times  12  ft.  there  are  in  the  given  whole.  Thus— if  purchasing 
deals — 


7 

of  6  ft. 

6  X  7  =  42  ft, 

5 

„  14  „ 

14  X  5  =  70  „ 

11 

11  ^"^  11 

19  X  11  =  209,, 

and  6 

„  21  „ 

21  X  6  =  126,, 

12)447(37-25  standard  deals. 

Prices. — In  London,  a  different  system  of  charging  sawing  of  deals  is  adopted  to  that 
in  the  provinces,  viz.  cuts  are  charged  so  much  per  dozen,  the  price  varying  with  (he 
length  ;  ripping  being  called  flat-cuts  in  the  same  way.   In  the  country  method,  all  cuts 


182 


Carpentry — Woods ;  Tools. 


in  tlic  (leal  or  log  are  charged  for  at  per  100  ft.  super,  and  all  rips  or  flat-cuts  under 
6  in.  are  charged  at  per  100  ft.  lineal ;  herewith  are  the  usual  prices  for  this  work,  viz.  :— 


Oak 

Mahogany         

Memel       

Swede  and  Yellow  Pine 

Pitch  Pine        

Deals 

Planing  Deals 

Chipping  do 

Matching,  Rebating,  or  Grooving 


I\-r  100  ft. 
super. 


s.  d. 
4     0 


5 
2 
2 
3 
1 
1 


G 
G 
3 
9 
9 
G 


Ripping  per 
100  ft.  rim. 


X  Cuts. 


s.  d. 

1  6 

1  6 

1  0 

0  10 

1  6 
0  9 


d. 

each  4 

„     * 
.,    2| 

„     3 

„       03 


1     0 

for  Hoop  Iron,  3(7.  per  100  ft.  super. 


Tools. — Carpenters'  tools  may  conveniently  be  divided  into  7  classes,  as  follows: — 
(1)  Guiding  tools— rules,  lines,  squares ;  (2)  Holding  tools— pincers,  vice  ;  (3)  Rasping 
tools— saws,  files ;  (4)  Edge  tools— chisels,  planes ;  (5)  Boring  tools— awls,  gimlets, 
bits ;  (G)  Striking  tools— hammers,  mallets ;  (7)  Chopping  tools— axes,  adzes.  In  an 
eighth  category  may  he  put  such  important  accessories  as  the  carpenter's  bench,  nails, 
screws,  and  various  hints  and  recipes. 

GuiDiXG  TOOLS.— These  comprise  the  chalk  line,  rule,  straight-edge,  square,  spirit 
level,  A-level,  plumb  level,  gauges,  bevel,  mitre-box,  calliiXirs  and  compasses,  trammel, 
and  a  few  modern  contrivances  combining  two  or  more  of  these  tools  in  one. 

Chalk  line.— The  chalk  line  is  used  as  shown  in  Fig.  242  for  the  purix)so  of  markhig 
where  cuts  have  to  be  made  in  wood.     It  consists  of  several  yards  of  cord  wound  on  a 


-42, 


wooden  reel,  and  well  rubbed  with  a  piece  of  chalk  (or  charcoal  when  a  white  line  would 
be  invisible)  just  before  use.  In  applying  it,  first  mark  with  the  carpenter's  pencil^  the 
exact  spots  between  which  the  line  is  to  run,  then  pass  a  bradawl  through  a  loop 
near  the  end  of  the  cord  and  fix  it  firmly  in  the  wood  at  the  first  point  marked,  next 
apply  the  chalk  or  charcoal  to  the  cord,  or  as  much  of  it  as  will  suffice  for  the  length  of 
line  to  be  marked,  this  done,  stretch  the  cord  tightly  to  the  second  point  marked,  and 
cither  fasten  it  by  looping  it  round  a  second  bradawl,  or  hold  it  very  tightly  in  the 
finger  and  thumb  of  one  hand,  whilst  with  the  finger  and  thumb  of  the  other  hand  you 
raise  it  in  the  middle  as  much  as  it  will  stretch ;  on  suddenly  releasing  it,  it  springs 
back  smartly  and  leaves  a  well-defined  Hue  between  the  two  points.  The  novice  may 
find  it  helpful  to  mark  both  sides  of  his  work,  which  is  best  done  by  removing  the 
cord  without  disturbing  the  bradawls. 

Jtule.—The  foot  rule  consists  of  a  thin  narrow  strip  of  metal,  hard  wood,  or  ivory, 
generally  2  ft.  long,  graduated  on  both  sides  into  inches  and  fractions  of  an  inch  (halves, 
4ths,  8ths,  12ths,  IGths,  32ndths),  and  hinged  so  as  to  fold  mto  a  shorter  compass  for 
convenience  in  carrying.  Superior  kinds  are  fitted  with  a  sliding  brass  rule  adding 
another  foot  to  the  length,  and  graduated  in  minute  subihvisions  which  facilitate  calcu- 
lations of  dimensions.  In  the  form  shown  in  Fig.  243,  known  as  "  Stanley's  No.  32," 
this  brass  slide  is  furnished  with  an  elbow  at  the  end,  so  that  it  constitutes  a  combined 


Carpentry — Guiding  Tools. 


183 


rule  and  calliper  (see  p.  189).  Ordinary  prices  are  Is.  to  5s.,  according  to  quality  and 
finish. 

Straight-edge. — The  nature  of  this  tool  is  expressed  in  its  name.  It  consists  of  a 
long  (5  or  G  ft.)  strip  of  well-seasoned  wood  or  of  bright  hardened  steel  (uickel-plated  if 
preferred;,  several  inches  wide,  having  at 

least  one  edge  perfectly  level  and  true  243. 

throughout.  Its  use  is  for  ascertaining 
whether  a  surface  is  uniformly  even, 
which  is  readily  done  by  simply  laying 
the  straight-edge  on  the  surface,  when 
irregularities  of  the  surface  become 
ajiparent  by  spaces  between  the  two 
planes  in  contact.  Steel  straight-edges 
are  made  with  one  bevelled  edge  and 
with  English  or  French  scales  graduated 
on  them. 

Squares. — The  use  of  these  instruments 
is  for  marking  out  work  at  right  angles. 

The  most  usual  forms  are  illustrated  below.  Fig.  244  is  a  common  brass-mounted  square  ; 
Fig.  245  a  mitre  square.  It  consists  generally  of  a  wooden  stock  or  back  with  a  steel 
blade  fitted  into  it  at  right  angles,  and  secured  by  3  screws  or  rivets ;  the  sizes  vary 
from  3  to  30  in.,  and  the  prices  from  Is.  to  10s.  They  are  also  made  of  plain  or  nickel- 
plated  steel,  with  scales  engraved  on  the  edges.  In  use,  the  stock  portion  of  the  square 
is  placed  tight  against   the   edge  which  forms  the  base  of  the  line  to  be  marked,  so 


o   o 


244. 


245. 


that  the  blade  indicates  where  the  new  line  is  to  be  drawn.  The  making  and  application 
of  squares  have  been  well  described  by  Lewis  F.  Lyne  in  the  Aviericun  Machinist.  He 
remarks  that  the  2  sides  of  a  square  should  form  an  angle  of  90^,  or  the  5  of  a  circle  ; 
but  hundreds  of  tools  resembling  squares  in  appearance,  and  s<!>  named,  when  the  test 
is  applied  to  them,  are  found  entirely  inaccurate  :  the  angle  is  in  some  instances  more, 
and  in  others  less,  than  a  right  angle.  The  way  these  tools  are  generally  made  is  by 
taking  a  piece  of  steel  for  the  stock,  planing  it  uj)  to  the  right  size,  and  squaring  up  the 
ends,  after  which  a  slot  is  cut  in  one  end  to  receive  the  blade.  The  blade  is  neatly 
fitted  and  held  securely  by  2  or  3  rivets  passing  through  the  end  of  the  stock  and 
blade.  It  is  a  very  ditficult  undertaking,  witii  ordinary  appliances,  to  cut  this  slot  pre- 
cisely at  right  angles  to  the  sides  and  ends  of  the  stock;  and,  when  the  blade  is  finally 
secured,  it  will  be  found  that  it  leans  to  one  side  or  the  other,  as  shown  in  Fig.  246,  where 
a  represents  the  stock,  and  b  the  blade  ;  c  is  an  end  view,  the  dotted  lines  showing  the 
position  of  blade,  as  described. 

The  best  way  to  produce  a  square  without  special  tools  is  to  make  a  complete  flat 
square  of  the  size  desired  out  of  thin  sheet  steel,  the  thickness  depending  upon  the 
size  of  square  desired.  In  almost  every  instance  where  squares  are  made  by  amateurs 
at  tool-making,  the   blades   are  left  too  thick.    After  the  square  has  been  trued   up 


184 


Carpentry — Guiding  Tools. 


and  finished  upon  the  sides,  2  pieces  of  flat  steel  should  be  made  exactly  alike  as  to 
size,  to  bo  riveted  upon  the  sides  of  the  short  arm  of  tlie  square  to  form  the  stock. 
To  properly  locate  these  pieces,  the  square  should  be  placed  upon  a  surface  plate,  and 
the  parts  clamped  in  position,  care  being  taken  to  get  them  all  to  bear  equally  upon  the 
surface  plate,  after  which,  holes  may  be  drilled  and  countersunk,  and  the  rivets  inserted. 
The  angle  formed  by  the  cutting  edges  of  the  drills  for  countersinking  the  holes  should 
be  about  60°,  so  that  when  the  livets  are  driven,  and  the  sides  of  the  back  finished,  there 
will  be  no  trace  kft  of  the  rivets,  which  should  always  be  of  steel. 

Close  examination  may  reveal  the  fact  that  the  blade  is  -winding,  or  is  slightly 
inclined  to  one  side.  If  inclined,  as  shown  at  e,  in  Fig.  2-l(J,  the  end  of  the  blade  only 
will  touch  a  square  piece  of  work  when  the  tool  is  held  in  a  proper  position,  as 
shown  in  Fig.  247,  where  i  represents  the  piece  of  work,  and  /  the  square.  It  is  a 
cirstom  among  machinists  to  tip  the  stock,  as  shown  at  /;  and  I,  to  enable  the  work- 
man to  see  light  under  the  blade.  This  only  aggravates  any  imperfection  in  the 
squareness  of  the  blade,  for  when  the  stock  is  tipped,  as  shown  at  Jc,  it  will  touch 

€ 


246. 


247. 


(I 


fie 


J 


[ '   / 

/      (  1 

r^   _=. 

'tf?'«F^-G:-tf>:r.r_-^- . -"■  - — 1 

9 
h 

'7> 

V 

z 

'^' 

f 

.1 1 

the  work  at  jr,  occupying  the  position  indicated  by  the  dotted  lines  3,  gr;  whereas,  if  the 
stock  be  tipped,  as  shown  at  Z,  the  blade  will  assume  the  position  indicated  by  the 
dotted  lines  h,  h.  These  conditions  will  exist  when  the  blade  of  the  square  is  in- 
clined, as  shown  at  e,  in  Fig.  246.  If  the  blade  is  inclined  to  the  left,  a  precisely 
similar  condition  will  exist,  except  in  the  reverse  order.  It  is  next  to  an  impossi- 
bility to  perform  accurate  work,  or  test  the  same  with  a  square  having  a  thick  edge, 
because  of  the  reason  already  stated  that  the  light  caimot  be  seen  between  the  edge 
of  the  blade  and  the  work. 

The  most  ingenious  tool  for  overcoming  the  foregoing  difficulties  is  a  sort  of  self- 
proving  square,  made  by  a  machinist  in  New  York.  This  is  shown  in  Fig.  248,  and 
consists  of  a  steel  beam  j,  shown  in  bottom  view  at  k.  In  the  end  of  this  beam  is 
a  hole  for  the  reception  of  a  screw,  with  a  common  bevelled  head.  A  square  piece 
of  steel,  I,  m,  forms  the  blade  of  this  square,  n  representing  the  end  of  the  blade. 
The  blade  is  first  planed,  then  tapped  and  hardened,  after  which  it  is  ground  to 
bring  the  tides  exactly  parallel  and  of  equal  size,  which  makes  the  bar  perfectly 
square.  The  stock  is  of  a  rectangular  section,  and,  with  this  exception,  is  hardened 
and  ground  in  the  same  manner  as  the  blade.  The  end  .nr  the  screw  is  then  carefully 
ground  at  right  angles  to  the  sides,  after  which  the  parts  are  put  together  and  the  screw 
is  tightened.  If  the  blade  is  not  precisely  at  rig^  t  angles  to  the  stock,  it  will  occupy  a 
position  indicated  by  the  dotted  line  0 ;  then,  if  the  screw  be  loosened  and  the  blade 
turned  half  a  revolution,  the  edge  will  stand  as  shown  by  the  dotted  line  at  p. 

The  end  must  be  so  ground  that  the  blade  will  occupy  precisely  the  same  relation  to 
the  beam  when  turned  in  all  positions.  When  this  is  accomplished,  the  square  is  a  very 
close  approximation  to  perfection.  The  accuracy  of  work  is  tested  with  one  of  the 
corners;  when  it  becomes  worn,  another  may  be  turned  into  position  ;  and  when  all  are 


CARrENTRY- 


-Guiding  Toolso 


185 


worn,  the  blade  is  removed  and  truod  up  by  grinding,  as  at  first.  In  testing  the  accu- 
racy of  the  ordinary  square,  it  is  usually  placed  upon  a  flat  surface  having  a  straij^ht 
edge,  as  shown  in  Fig.  249,  where  s  represents  tlie  surface  with  the  square  upon 
it.    The  stock  is  pressed  firmly  against  the  edge  of  the  surface,  and  with  a  scriber 


248. 


Ttb 


219. 


Q' 

\k 

^' 

1  ■ 

ty 

1 
1 

a^...— 

.— ! 

a  fine  line  is  drawn  along  the  edge  of  the  blade.  The  square  is  then  turned  to  the 
position  f,  indicated  by  the  dotted  lines,  and  a  second  line  is  drawn  along  tlie  edge 
of  the  blade.  If  the  tool  is  less  than  a  right  angle,  the  line  with  the  square  in  the 
former  position  will  incline  towards  g,  while  in  the  latter  position  it  will  appear  as 
shown  at  r\  whereas,  if  the  square  be  correct,  the  two  lines  will  exactly  coincide  with 
each  other.  This  is  not  a  reliable  test  for  the  accuracy  of  a  square,  but  it  answers  very 
well  in  case  of  emergency. 

It  is  difficult  to  draw  the  lines  to  exactly  represent  the  edge  of  the  blade,  owing  to 
the  fact  that  the  slightest  inclination  of  the  hand  holding  the  scribtr  to  either  side 
will  make  a  crooked  line.  The  form  of  square  shown  in  Fig.  248  always  presents  a 
fine  edge  to  work  to,  and  may  always  be  relied  upon  for  accuracy  when  properly  fitted 
up.  This  square  would  seem  to  be  quite  as  easily  made  as  tlie  common  one,  but  the 
construction  of  an  accurate  square  with  ordinary  appliances  is  a  job  that  tests  the  skill 
of  a  good  workman. 

S]}irlt  level. — The  spirit  level  consists  of  a  glass  tube  partially  filled  with  spirit, 
encased  in  a  framework  made  of  hard  wood  and  protected  by  metallic  facing  on  the  most 
important  sides.     The  quantity  of  spirit  placed  in  the  glass  tube  is  just  insufficient  to 

250. 


fill  it,  so  that  a  "  bubble  "  of  air  perhaps  i  in.  long  always  appears  at  the  surface,  being 
rendered  visible  by  means  of  a  sight-hole  in  the  metidlic  plate  which  encloses  and 
secures  the  glass  tube  in  the  wooden  block.  The  ends  of  the  glass  tube  are  hermetically 
sealed  when  tlie  proper  quantity  of  spirit  has  been  introduced.  The  wooden  case  or 
block  must  be  perfectly  level  and  true,  and  of  a  material  that  will  not  change  its  form 
by  climatic  or  other  influences.    Average  sizes  arc  8-1-1  in.  in  length  and  cost  2-lOs. 


186 


Caepentet — Guiding  Tools. 


Some  are  made  with  the  sight-hole  at  the  side  instead  of  the  top.  Others  have  both  top 
and  side  openings.  Such  is  shown  in  Fig.  250,  which  represents  Stanley's  improved 
adjustable  combined  spirit  and  pliunb  level,  by  whicli  it  is  possible  to  adjust  a  surface  to 
a  position  both  truly  horizontal  and  truly  perpendicular.  The  principle  of  action  of  the 
spirit  level  is  that  the  air  bubble  contained  in  the  glass  tube  will  always  travel  towards 
the  highest  point;  when  it  rests  immediately  in  the  centre  of  tlie  sight-hole,  a  true 
level  is  obtained.  It  is  necessary  to  remember,  however,  that  it  is  only  a  guide  to  the 
level  of  that  length  of  surface  on  which  it  lies ;  and  in  levelling  longer  surfaces  the 
spirit  level  should  be  jilaced  on  a  straight-edge  instead  of  du-ectly  on  the  surface  to  be 
tested. 

Plumb  level. — This  consists  of  a  straight-edge  to  which  is  attached  a  cord  liaving  a 
weight  suspended  from  the  end,  as  shown  in  Fig.  251.  The  top  end  a  of  the  straight- 
edge has  3  saw-cuts  made  in  it,  one  being  exactly  in  the  centre.  From  this  centre  cut  a 
line  is  drawn  perfectly  straight  to  the  other  end  h.  On  this  line  at  c  a  pear-shaped  hole 
is  cut  out  of  the  straight-edge.  A  piece  of  supple  cord  is  next  weiglited  by  attacliing  a 
pear-shaped  lump  of  lead,  and  then  fastened  to  the  top  a  of  the  straight-edge  by  passing 
it  iirst  through  the  central  saw-cut,  and  then  through  the  others  to  make  it  fast,  just  so 
that  the  leaden  weight  is  free  to  swing  in  and  out  of  the  hole.  The  law  of  gravity 
forces  tlie  cord  to  hang  (when  free)  in  a  truly  upright  (perpendicular)  position;  on 

251. 


d 


& 


0/ 


^0 


252. 


c 


"4=3' 


^ 


D 


y 


253. 


c 


{^iii^muiL 


placing  the  side  d  of  the  straight-edge  against  a  surface  e,  whose  perpendicularity  is  to 
be  tested,  if  there  is  any  disagreement  between  the  cord  and  the  line  marked  on  the 
straight-edge,  then  the  surface  is  not  upright,  and  it  must  be  altered  until  the  cord 
exactly  corresponds  to  and  covers  the  line  marked  down  the  centre  of  the  straight- 
edge. 

Gauf/es.— There  are  3  kinds  of  gauge  used  in  carpentry,  known  respectively  as  the 
"marking,"  the  "cutting,"  and  the  "mortice"  gauge.  They  are  outlined  in  the  annexed 
illustrations.  Fig.  252  is  a  cutting  gauge  having  the  head  faced  with  brass  ;  Fig^  253  is 
an  improved  form  of  cutting  gauge ;  Fig.  251  is  a  thumb  or  turn-screw  screw-slide  mortice 
gauge ;  Fig.  255  is  an  improved  mortice  gauge  with  improved  stem.  The  marking  gauge 
has  a  shank  about  9  in.  long  with  a  head  or  block  to  slide  along  it ;  a  spike  is  inserted 
near  the  end  of  the  shank,  and  the  movable  head  is  fixed  at  any  required  distance  from 
the  spike  by  a  screw  or  wedge ;  its  use  is  to  make  a  mark  on  the  wood  parallel  to  a 


CxiRPENTRY— Guiding  Tools. 


187 


previously  straightened  edge,  along  wliicli  edge  the  gauge  is  guidotl ;  for  dressing  up 
several  pieces  of  wood  to  exactly  the  same  bieadtli  this  gauge  is  eminently  useful.  The 
cutting  gauge  is  similarly  composed  of  a  shank  and  a  head,  but  tlic  spike  is  replaced  by 
a  thin  steel  plate,  passing  through  the  shank  and  secured  by  a  screw,  and  sharpened  on 
one  edge  so  as  to  be  capable  of  making  a  cut  either  with  or  across  the  grain;  its  main 
applications  are  for  gauging  dovetailed  work  and  cutting  veneers  to  breadth.     The 

254.  nrr 


mortice  gauge  resembles  the  others  in  having  a  shank  (about  G  in.  long)  and  a  movable 
brass-shod  head,  but  it  has  2  spikes,  one  fixed  and  the  other  arranged  to  be  adjusted  by 
means  of  a  screw  at  varying  distances  from  the  first ;  it  is  used  for  gauging  mortice  and 
tenon  work.  Gauges  are  generally  made  of  beech,  and  the  shank  is  often  termed  the 
"strig";  compound  gauges  are  now  made,  consisting  of  marking  and  cutting,  or 
marking  and  mortice  appliances  combined  in  one  tool.  Prices  vary  from  3d.  to  10s., 
according  to  finish.  In  using  the  gauge,  the  marking  point  is  first  adjusted  to  the 
correct  distance,  then  secured  by  turning  the  screw,  and  the  mark  is  made  when  required 
by  holding  the  head  of  the  gauge  firmly  against  the  edge  which  forms  the  basis  of  the 
new  lines,  with  the  marker  resting  on  the  surface  to  be  marked,  and  passing  the 
instrument  to  and  fro. 

Bevels.— These  differ  from  squares,  in  that  they  are  destined  for  marking  lines  at 
angles  to  the  first  side  of  the  work,  but  not  at  right  angles.    Examjjles  are  shown  in  the 


256. 


257. 


258. 


-annexed  illustrations.  Fig.  256 
is  an  ordinary  angle  bevel; 
Fig.  257  is  an  improved  me- 
tallic frame  sliding  bevel;  and 
Fig.  258  is  a  boat-builder's  bevel 
with  2  brass  blades.  The  bevel 
is  used  in  precisely  the  same 
manner  as  the  try  square.  A 
very  useful  bevel  protractor,  with  a  sliding  arm  and  half  circle  divided  into  degrees,  is 
sold  by  Churchills. 

Mdre-ho.v. — The  mitre-box  is  an  arrangement  for  guiding  a  saw-cut  at  an  angle  of  45° 
exactly,  or  half  the  dimensions  of  a  right  angle.  It  is  mostly  required  for  cutting 
mouldings,  where  the  end  of  one  piece  of  wood  meeting  the  end  of  another  has  to  form 
with  it  a  true  corner  of  90°  (a  right  angle).  The  best  illustration  of  a  mitre  is  to  be 
seen  m  either  of  the  4  corners  of  a  jjicture  frame.     lu  its  simplest  form  the  mitre-box 


188 


Caepextry — Guidiutr  Tools. 


239. 


may  be  made  out  of  any  piece  of  good  sound  plank  li  ft.  long  and  say  6  in.  by  3  in.  A 
rebate  is  cut  lengthwise  in  this,  i.e.  half  its  width  and  half  its  thickness  is  cut  away, 
leaving  the  slab  in  the  form  of  2  steps,  thus  constituting  a  rest  for  any  work  to  be 
operated  upon.  Next  "2  saw-cuts,  one  lacing  each  way,  are  carried  down  through  the 
top  step  and  about  J  in.  into  the  lower  step,  these  saw-cuts  being  exactly  at  an  angle 
of  45°  with  tlie  front  edge  of  the  '*  bos." 
When  a  mitre  has  to  be  cut,  the  wood  to  be 
operated  on  is  laid  on  the  lower  step  and 
hold  firmly  into  the  angle,  while  a  saw  is 
passed  down  in  the  old  cuts  in  the  box  and  so 
through  the  wood  to  be  mitred. 

For  cutting  other  angles  than  45^,  other 
saw-cuts  might  be  made  in  the  same  box ; 
but  the  most  convenient  instrument  for  cutting 
a  wide  series  of  angles  is  the  I.angdon 
raitre-box,  sold  by  Churchills,  and  illustr.ited 
in  Fig.  259.  Wliilst  ordinary  mitre-boxes 
range  only  from  right  angles  (00^)  to  45'^,  this 
cuts  from  riglit  angles  to  73^  on  2i-in.  wood, 
and  is  tlie  only  form  adjustable  for  mitreing 
circular  work  in  patterns  and  segments  of 
various  kinds.  Prices  range  between  248.  and 
70s.  without  the  saw,  according  to  depth  and 
width  of  cut. 

The  ordinaiT  mitre-bos  mny  also  be  made 
in  the  form  of  a  wide  shallow  trough,  the 

saw-cuts  at  an  angle  of  45^  being  carried  down  through  the  sides  to  the  floor,  while  the 
sides  and  floor  combined  form  the  rest  for  the  work  in  hand. 

All  the  forms  of  mitre-box  described  above  are  intended  for  use  with  a  saw,  the 
edges  of  the  mitre  being  left  rough  from  the  saw  in  order  to  take  glue  better. 

261. 


Another  form,  admitting  of  the  sawed  work  being  planeil  up,  is  c.illed  a  "  shooting- 
board,"  and  is  shown  in  Fig.  260.  It  consists  of  2  slabs,  a  h,  of  good  sound  mahogany, 
aboirt  30  in.  long,  IS  in.  wide,  and  1  in.  thick,  screwed  together  so  as  to  form  a  step  c ;  on 
the  topmost  are  screwed  2  strips  d  of  hard  wood  11-2  in.  wide,  at  riglit  angles.  The 
piece  of  moulding  e  to  be  mitred  is  laid  agi^inst  one  guide  bar.  and  sawn  ofl'  on  the 
line  c,  or  laid  on  the  other  side  against  the  second  guide  bar,  and  similarly  cut  off.  It 
will  be  necessary  to  use  both  sides  in  this  way,  because,  although  the  piece  cut  oS"  has 


Carpentry— Guiding  Tools. 


189 


also  an  angle  of  45^,  it  would  need  to  be  turned  over  and  applied  to  the  other,  which 
could  not  be  done  without  reversing  the  moulding.  In  a  plain  unmoulded  strip,  this 
would  not  signify.  The  strip  lying  close  to  the  btcp  or  rebate  of  the  board,  can  bo 
trimmed  by  the  plane  by  laying  it  on  its  side,  but  care  must  be  taken  not  to  plane  the 
edge  of  the  step  itself.   The  plane  must  be  set  very  fine,  and  must  cut  keenly.   To  saw  off 


262. 


a  piece  at  right  angles,  and  not  with  a  mitre,  lay  it  against  the  bar,  and  saw  it  oft' in  a  line 
with  the  other,  when  it  cannot  fail  to  be  cut  correctly,  d  d  forming  2  sides  of  a  square. 
A  handy  mitreing  tool  sold  by  Melhuish  is  shown  in  Fig.  2G1.     It  cuts  a  clean 


264. 


mitre  at  one  thrust  of  the  nandle.    Its  price  is  15s.  to  cut  2-in.  mouldings,  and  30s. 
for  4-in. 

Compasses  and  Callipers. — Tliese  implements  are  used  for  taking  inside  and  outside 
dimensions  where  a  rule  cannot  be  employed,  and  for  striking  out  circular  figures. 
Ordinary  forms  are  shown  in  the  annexed  diagrams.    Fig.  262  is  a  pair  of  ordiuary  plaiu 


190 


Carpentey — Guiding  Tools. 


compasses ;  Fig.  263,  wing  compasses ;  Fig.  264,  spring  callipers ;  Fig.  265,  inside  and 
outside  callipers ;  Fig.  266,  improved  inside  and  outside  callipers.    The  method  of  using 


these  instruments  is  sufficiently  obvious  from  their  shape.    Ordinary  useful  sizes  vary 
in  price  from  1  to  5s. 

Trammel. — This  is  employed  for  drawing  elliptic  or  oval  curves,  and  is  represented 
in  Fig.  267.  It  can  be  purchased  with  varying  degrees  of  finish,  or  may  be  home  made 
in  the  following  manner: — Two  strips  of  dry  hard  wood  a,  18  in.  long,  IJ  in.  wide,  and 
f  in.  thick,  are  ploughed  down  the 
centre  to  a  depth  of  f  in.  and  a  width 
of  I  in. ;  one  is  let  into  the  other  at 
right  angles  so  that  the  bottoms  of  the 
grooves  or  channels  are  exactly  flush, 
a-ad  the  structure  is  strengthened  by 
having  a  piece  of  thin  sheet  brass  cut 
to  the  shape  and  screwed  down  to  its 
upper  surface.  Next  2  hard-wood 
blocks  IJ  in.  long  are  cut  to  slide 
easily  but  firmly  in  these  grooves, 
their  surfaces  coming  barely  flush  with 
the  face  of  the  instrument.  A  hole  is 
drilled  nearly  through  the  centre  of 
each  block  and  about  -^^  in  diam.,  to 
admit  the  pins  h ;  and  thin  strips  of 
brass  are  then  screwed  on  to  the 
surface  of  the  instrument  in  such  a 
manner  as  to  secure  the  blocks   from 


coming  out  of  the  grooves  while  not  interfering  with  the  free  passage  of  the  pins  and 
blocks  along  the  grooves.  To  this  is  added  the  beam  compass  c,  which  consists  of  a 
straight  mahogany  ruler  with  a  narrow  slit  down  the  middle  permitting  it  to  be  adjusted 
on  the  pins.  These  last  may  be  of  brass  or  steel  wire  with  a  shoulder  and  nut,  as  at  d ; 
they  are  fixed  at  the  required  points  on  the  ruler  c,  and  then  inserted  in  the  holes  in 
the  blocks,  where  they  are  free  to  revolve.  A  hollow  brass  socket  e  fitted  with  a  pencil 
is  also  made  to  screw  on  to  the  beam,  and  forms  the  delineator. 

Shooting-hoard. — This  implement,  Fig.  268,isfor  the  purpose  of  securing  a  true  surface 
and  straight  edge  on  wood  when  planing.  It  is  generally  made  by  fastening  one  board 
on  another  in  such  a  way  as  to  form  a  step  between  them ;  shooting-boards  made  by 
gluing  2  jDieces  of  board  together,  are  very  apt  to  twist  and  cast  through  the  action  of 
the  air,  and  once  out  of  square,  are  very  hard  to  set  right,  generally  requiring  to  be  puUed 
apart,  and  made  again.  The  following  plan  renders  this  unnecessary: — Take  2  boards 
(of  the  length  you  require  the  board,  allowing  at  least  1  ft.  extra  for  the  plane  to  run ; 


Caepentey — Guidiuii;  Tools. 


191 


tliug,  to  plane  up  5-ft.  stuff,  make  the  board  at  leabt  G  ft.)  of  thorouglily  dry  pino,  1  in. 
thick  and  11  in.  wide,  and  plane  them  perfectly  true;  cut  4  in.  off  oue  the  whole  lengtli 
of  the  board;   these  2  pieces  are  for  the  bottom  board,  and  across  these  glue  about 


Cr-. 

d 


T  / 


C', 


268. 


Sr 


Up 


*¥" 


^ 


^, 


a 


± 


^ 


¥ 


76. 


--y 


/■ 


8  pieces  of  J.-in.  pine  IJ  in.  ■wide  by  10  in.  in  length  and  one  piece  5  in.  in  width  by 
10  in.  in  length  to  build  up  or  strengthen  the  upper  board  where  the  groove  will  come, 
leaving  a  gajD  4  in.  wide  between  the  2  bottom  boards,  thus  making  it  15  in.  wide ;  now 
glue  on  the  upper  board,  allowing  it  to  lap  1  in.  over  the  cross-pieces  (as  in  cross 
section),  and  screw  together  with  2  1-in.  screws  from  the  bottom.  This  will  allow  the 
top  to  be  planed  if  it  should  cast,  as  the  screws  do  not  come  through,  and  the  edge 
being  raised  and  lajDpiug  over  the  cross-pieces,  allows  the  edge  to  be  squared,  without 
parting  the  boards,  while  the  air  having  free  play  all  round  the  boards  they  are  not  sO' 
likely  to  cast,  and,  in  shooting  an  edge,  the  shavings  and  dust  woik  away  under  the 
top  board,  so  as  not  to  throw  the  plane  out  of  square.  The  blocks  are  generally  screwed 
across  the  board,  but  it  is  better  to  cut  a  groove  across,  wedge-shape,  6  in.  from  the 
end,  and  cut  wedges  of  various  thicknesses  for  planing  wood  of  any  substance,  so  that 
the  plane  may  nm  over  the  block,  as  in  section.  The  measurements  are  a-b,  4  in. ; 
fc-c,  4  in. ;  c-d,  7  in. ;  d-e,  6  ft. ;  f-cj,  10  in. ;  g-li,  5  in. ;  h-h,  4  in. ; 
and  in  the  section  of  the  boards,  a-h,  11  in. ;  c-d,  15  in. 

Bell  centre  ■punch. — This  handy  little  device  enables  any  mechanic 
instantaneously  to  centre  any  round,  square,  oval,  triangular, 
hexagonal,  or  octagonal  article  for  the  purpose  of  drilling  or  turning. 
In  use  the  pimch  is  held  upright  (as  shown  in  Fig.  269)  over  the 
article  to  be  centred,  and  the  punch  centre  tapped,  when  the 
true  centre  of  any  geometrically-shaped  article  will  be  found.  It 
will  centre  any  size  from  J  to  1  in.  diam.,  and  costs  from  3s. 
upwards. 


269. 


270, 


C&D  ^ptW 


Co?n6t?!a<i'ons.— Combination    tools  are  essentially  American  noveltie?,  and   those 
described  here  may  all  be  obtained  of  Cburchills,  Finsbury, 

Starrett's  calliper-square  is  shown  in  Fig.  270 ;  the  jaws  are  hardened,  and,  being 


192 


Caepentky— Guidins:  Tools. 


made  independent  and  accurately  ground,  can  be  reversed  for  an  inside  calliper  of 
larger  scope,  or  used  for  depth  gauge,  &c.  The  beam  is  graduated  to  G4tlis  in.  on 
one,  and  lOOths  on  the  other.  The  4-in.  size  costs  18s.  with  adjusting  screw,  or  14s. 
without. 

The  steel  calliper-rule  is  shown  in  Fig.  271 ;  when  closed  it  is  3  in.  long,  and  the 


271. 


001 


16 


o" 


3: 


oz 


04 


ililliliililiiilillililt 


64 


J  I 


M 


calliper  can  be  drawn  out  to  measure  21  in.     They  are  accurately  graded,  and  durable; 
cost,  15s.  9d. 

Starrett'd  combined  try-square,  level,  plumb,  rule,  and  mitre,  is  shown  in  Fig.  272; 
the  various  parts  are :  a,  centre  hiad  forming  centre  square  both  inside  and  outside, 
one  scale  iitting  both  heads ;  h,  square ;  c,  mitre ;  d,  rule ;  e,  plumb  level.  As  a  try- 
square,  it  is  a  substitute  for  every  size  of  the  common  kind,  and  more  compact ;  as  a 
centre  square,  it  gives  both  inside  and  outside  grades ;  as  a  mitre,  it  affords  both  long 


212. 


'iiiiiimi|iil|lll|limilllHIIII]lll|l|l|ll||lii]llii 

lillmlid' 


12  3 

y.l^lilJ,iihHliMl,lllnlll'lllMlllllml.i 


{in{iii|i{i{iii|iii|iiiirii|iii{i 

'       t        '      2  3  4 


illil!llUill!llT-lTllTllllll!llllllllMllllllllllMlllllllul,llnl,,lMlllllllllllllllllllll 


and  short  tongues ;  and  it  can  be  used  as  a  marking  gauge,  mortice  gauge,  or  f-square. 
Tlie  4-iu.  size  witliout  centre  head  or  level  costs  4s.  Gd.,  and  the  compdete  tool  may  be 
had  for  lis.  3d.  for  the  6-in.  size  to  15s.  9d.  for  the  12-in. 

Ames's  universal  or  centre  square  is  shown  in  Fig.  273.  For  finding  the  centre  of  a 
circle,  as  in  A,  the  instrument  is  placed  with  its  arms  b  a  e  resting  against  the  circum- 
ference, in  which  position  one  edge  of  the  vertical  rule  a  d  will  cross  the  centre.  "  If  a 
line  be  drawn  here,  and  the  instrument  be  similarly  applied  to  auotlier  section  of  the 
circumference,  and  another  line  be  drawn  crossing  the  first,  the  point  of  crossing  will  be 
the  centre  of  the  circle.    B  illustrates  its  use  as  a  try-square  at  n,  and  as  an  outside 


Cakpentrt- 


-Holding  Tools. 


193 


273 


square  at  I.  In  C  it  is  applied  aa  a  mitre,  in  D  as  a  rule  and  T-squarc,  in  E  as  an 
outside  square,  and  in  F  as  a  T-square  for  machinists.  The  prices  range  from  lis.  3d. 
for  the  4-in.  size  to  31s.  Grf.  for  the  12-in. 

HoLPiNG-TOOLs. — These  are  chiefly  repre- 
sented by  pincers,  vices,  and  clamps. 

Pincers. — This  well-known  tool  is  shown 
in  Fig.  274.  It  is  made  in  -various  sizes  and 
qualities,  the  most  generally  useful  being 
the  5-in.  and  8-in.  sizes,  costing  about  '3d. 
per  in. 

Vices. — The  old-fashioned  form  of  hand- 
vice  is  shown  in  Fig.  275  ;  in  size  and  price 
it  ranges  from  3-in.  and  2s.  to  6-in.  and  6s. 
Steer's  patent  hand-vice,  as  sold  by  Melhuish, 
Fetter  Lane,  is  represented  in  Fig.  276 ; 
cost  5s.  The  improved  American  hand-vice, 
as  sold  by  Churcliills  (Fig.  277),  is  of  metal 
throughout,  the  jaws  being  of  forged  steel, 
and  the  handle  of  case-hardened  malleable 
iron ;  price  6s.  6d.  The  2  last  forms  have  a 
hole  through  the  handle,  and  screw  for 
holding  wire.  An  ordinary  wrought-iron 
parallel  vice  is  shown  in  Fig.  278. 

Great  improvements  have  been  made  of 
late  years  in  vices,  more  especially  in  the 
American  forms  sold  by  Churchills.  The 
one  shown  in  Fig.  279  has  a  3-in.  jaw,  with 
swivel  base;  and  beckhorn  and  swivel-jaw 
attachment,  allowing  it  to  take  hold  in  any 

position  that  may  be  found  convenient ;  its  price  is  20s.  Fig.  280  illustrates  Parker's 
saw-filer's  vice,  made  with  a  ball-and-socket  joint,  by  which  the  jaws  may  be  turned  to 
any  position ;  price  7s.  for  9-in.  jaws.  Hall's  patent  sudden-grip  vice  is  shown  in 
Fig.  281.    To  open  the  jaws,  lift  the  handle  to  a  horizontal  position,  or  as  high  as  it 


274. 


276. 


■will  go,  and  draw  it  towards  you.  In  this  way  the  sliding  jaw  can  be  moved  to  any 
position,  and  the  vice  swivelled  if  desired.  In  order  to  grasp  the  work,  push  in  the 
sliding  jaw  till  it  presses  against  the  work,  then  depress  the  handle,  which  causes  the 


194 


Carpentry — Holding  Tools. 


jaws  to  securely  grasp  tlio  work  and  at  the  same  time  lock  the  swivel.    If  the  handle 
should  not  go  low  enough  for  convenience,  it  can  bo  made  to  go  lower  by  dei^ressing  it 
just  before  it  touches  the  work  to  be  held.     If  the  vice  swivels  too  easily,  drive  in  the 
key  W  in  the  bottom  plate ;  but  if 
it    does   not   turn    easily   enough, 
drive  out  the  key  a  little.     If  the 
handle   fails   to  remain  in  a  hori- 
zontal position,  the  screw  S  can  be 
tightened  to  hold  it.     Care  should 
be  taken  that  the  screw  N  is  down, 
so  as  to  keep  the  rack  H  from  lifting 


218. 


279 


with  the  clutch  G.  The  sliding  jaw  can  be 
removed  by  taking  out  the  pin  at  the  end  of 
the  slide,  keeping  the  handle  horizontal. 
If  grease  or  dirt  gets  on  the  rack  H,  the 
slide  should  be  withdrawn,  and  the  rack  and 
clutch  thoroughly  cleaned.  Sizes  and  prices 
vary  from  2-in.  jaw,  opening  2  in.,  weighing 
Gib.,  cost  22s.  Gd.,  to  5-in.  jaw,  opening  6  in., 
cost  95s. 

A  very  handy  little  "  instantaneous  grip  " 
vice,  sold  by  Melhuish,  Fetter  Lane,  is 
shown  in  Fig.  282 ;  the  size  with  9-iu.  jaws 
opening  12  in.  costs  16s. 

The  picture-frame  vice  illustrated  in  Fig.  283  is  a  useful  novelty,  sold  by  Churchills. 
It  is  operated  by  means  of  a  cam  lever  attached  to  a  treadle,  thus  allowing  entire 
freedom  to  both  hands  of  the  workman.    It  is  easily  and  quickly  adjusted  of  mouldiuga 


Carpentry — Holdino;  Tools. 


195 


of  any  width  and  frames  of  all  sizes ;  and  holds  both  pieces,  whether  twisted  or  straight, 
so  firmly  that  perfect  joints  are  made  without  re-adjusting  ;  price,  228.  6d. 

Stephens'  parallel  vice,  as  sold  by  Churchills,  is  shown  in  Fig.  284.    The  working 
parts  consist  simply  of  a  toggle  G  and  toothed  bar  T,  hold  together  by  a  spring  S,  and 


281. 


worked  by  a  cam  C,  and  hook  M,  on  the  handle  H.  Pressing  the  handle  hard  back, 
the  tooth  M  is  brought  to  bear  under  the  tooth  m,  on  the  left  joint  of  the  toggle,  thus 
disengaging  the  racks  by  raising  the  tooth  bar  t  away  from  the  rack  T.    The  movable 


'282. 


jaw  B  can  now  be  slid  in  and  out,  to  its  ex- 
treme limits,  with  perfect  ease,  and  an  article 
of  any  size  be  held  at  any  point  between 
these  limits,  simply  by  placing  it  between 
the  jaws  of  the  vice,  then  pressing  tlie  movable 
jaw  B  against  it  and  pulling  the  handle  out. 
At  the  first  start  of  the  handle  outward,  the 
tooth  M  slips  from  under  the  tooth  ni,  and 
the  spring  S  draws  down  and  firmly  holds  the 
tooth  bar  t  against  the  rack  T  ;  as  the  handle 
is    pulled    farther   outward,   the    cam   0   is 

brought  to  bear  against  the  ridge  n,  thus  straightening  the  toggle  and  forcing  the 
movable  jaw  B  against  the  article  to  be  held.  The  parts  are  interchangeable.  The 
racks  and  all  parts  where  pressure  cornea  are  made  of  steel.  ^  There  is  no  wear  to  the 

o  2 


ffl 


196 


Oarpentet — Holding  Tools. 


racks,  for  they  merely  engage  without  rubhing.  Great  solidity  and  strengtli  are  added 
to  the  movable  jaw  by  a  projection  from  the  stock  strengthened  by  two  upright  flanges 
Occasionally  put  a  drop  of  oil  on  the  cam  C  and  tooth  M. 


284. 


Fig.  285  represents  Stephens'  adjusting  taper  attachment,  for  holding  all  kinds  of 
taper  or  irregular  work ;  and  Fig.  286  illustrates  the  pipe  attachment  for  holding  gas- 
pipes  or  round  rods.      The  width  of  jaw  varies  from  2  to  6|  in.;  opening,  2J-11  in.; 


'  285. 


236. 


price  14-1 50s.  with  plain  base,  or  18-1 76s.  with  swivel  base;  taper  attachment  costs 
6-32s.,  and  pipe  attachment,  12s.  6d.-36s. 

Vices  also  form  an  essential  part  of  the  carpenter's  bench,  and  will  be  further  noticed 
under  that  section  (p.  261). 

Clamps. — The  ordinary  carpenter's  clamp  (or  cramp),  shown  in  Fig.  287,  is  employed 
for  tightening  up  the  joints  of  boards,  whether  for  the  purpose  of  nailing  or  to  allow 


Carpentry — Holding  Tools. 


197 


time  for  glue  to  harden.  It  is  composed  of  a  long  iron  bar  a  provided  with  holes  h  at 
intervals  for  receiving  iron  bolts  which  hold  the  sliding  bracket  c  ;  the  length  of  slide 
of  the  second  bracket  d  is  limited  by  the  screw  e  which  actuates  it.  The  length  of 
opening  varies  from  3  to  6  ft.,  cost  25-38s. 

Murphy's  bench  clamp,  as  sold  by  Churchills  for  148.  6d,  is  shown  in  Fig.  288.  It  is 


290. 


reliable,  does  not  injure  the  work,  is  adapted  to  any  thickness  of  29i 

bench  top,  can  be  changed  to  any  position,  and  laid  aside  when  not 
in  use. 

Hammer's  adjustable  clamp.  Fig.  289,  is  a  strong  tool  made  of 
malleable  iron  ;  prices  range  from  228.  6d.  a  doz.  for  the  3-in.  size, 
to  55s.  for  the  8-in. 

For  simple  rough  work  a  suitable  clamp  can  be  made  by  driving 
wedges  in  to  tighten  up  the  work  laid  between  stops  on  a  plank. 

A  very  useful  corner  clamp  for  securely  gripping  2  sides  of 
a  picture  frame  during  nailing  or  gluing  together,  is  shown  iu 
Fig.  290.  The  two  pieces  being  accurately  mitred  are  placed  in 
close  contact  and  so  held  while  the  clamp  is  being  tightened. 
These  clamps  are  sold  by  Melhuish  at  2s.  a  pair  for  taking  l|-in. 
mouldings,  up  to  5s.  for  4-in. 

Fig,  291  shows  a  clamp  designed  for  holding  a  circular-saw  while  being  filed :  a  has 
2  jaws,  one  of  which  is  seen  at  6 ;  they  are  of  metal  lined  with  wood,  and  are  closed  or 


198 


Carpentry — Holding  Tools. 


unclosed  by  turning  the  handle  c.  The  temporary  mandrel  of  the  saw  may  be  placed 
in  either  of  the  holes  oi  the  clamp  standards  at  d,  so  as  to  bring  the  saw  to  the  right 
height  in  the  jaws. 

Bench  clamps  and  holdfasts  will  be  described  under  another  section  (p.  259). 

Easping  Tools. — These  comprise  the  various  forms  of  saw  as  well  as  files  and 
rasps. 

Saws. — Tlie  saw  is  a  tool  for  cutting  and  dividing  substances,  chiefly  wood,  and 
consisting  of  a  thin  plate  or  blade  of  steel  with  a  series  of  sharp  teeth  on  one  edge, 
which  remove  successive  portions  of  the  material  by  cutting  or  tearing.  Some  repre- 
sentative examples  of  handsaws  are  illustrated  below :  Fig.  292  is  a  panel  and  ripping- 


29*>. 


293. 


vwwvw^VVWvvvvvVyv/MAMiWvv^MWNWAWAi 


295. 


saw  ;  Fig.  293,  a  grafter  saw  ,  Fig.  294,  a  tenon  saw ;  Fig.  295,  a  dovetail  saw ;  Fig.  296, 
an  iron  bow  saw  ;  Fig.  297,  a  frame  turning  saw. 

Principles. — The  saw  is  essentially  a  tool  for  use  across  or  at  right  angles  to  the  fibres  of 
the  wood,  although  custom  and 

convenience   have    arranged   it  294. 

for  use  along  the  fibres,  still  not  -=^=^=====^== 
when  those  fibres  are  straight 
and  parallel.  If  in  the  growth 
of  timber  there  was  not  any 
discontinuity  in  the  straight 
lines  of  the  fibres,  then  all  lon- 
gitudinal separation  would  be 
accomplished  by  axes  or  chisels. 
It  is  because  this  rectilineal 
continuity  is  interrupted  by 
branches  and  other  incidents  of 
growta  that  the  saw  is  used 
for  ripping  purposes.  Were  not 
some  tool  substituted  for  the 
wedge-like  action    of   the  axe, 

timber  could  not  as  a  general  rule  be  obtained  from  the  log  with  flat  surfaces.  Hence 
the  ripping  saw,  a  tool  which  is  intermediate  between  an  axe  and  a  saw  proper.  To 
study  the  saw  as  a  tool  fulfilling  its  own  proper  and  undisturbed  duties,  it  must  be 

296. 


Wv/V/'/*/-/s/WW^VsA^S^w»^/7S^A^WS^v/<AA(»iAA'S^A-^. 


regarded  in  the  character  of  a  cross-cut  saw.    In  this  character  it  is  called  upon  to  meet 
the  two  opposing  elements — cohesion  and  elasticity  of  fibre. 

To  deal  with  the  treatment  of  fibrous  wood  at  right  angles  to  the  length  of  the 


Carpentry — Kasping  Tools. 


199 


297. 


:):CZ> 


fibre  is  then  clearly  an  operation  in  which  considerations  must  enter,  differing  in  many 

respects  from  those  that  decide  action  in  direction  of  the  grain.     The  object  now  is,  as 

it  were,  to  divide  with  the  least  expenditure  of  power  a  string  which  connects  two  ends 

of  a  tensioned  bow.     If  a  blow  be  given  in  the  middle  of  a  bow-string,  the  elasticity 

imparted  by  the  bow  to  the  string  renders  the  blow  Inoperative.     Tiic  amount  of  this 

elasticity  is  very  apparent  when  one  notes  the  distance  it  can  project  an  arrow.     Indeed, 

any  one  who  has  struck  a  tensioned  cord  or  a  spring  is  well  aware  that  the  recoil 

throws  back  the  instrument,  and  by  so  mucli  abstracts  from  the  intensity  of  the  blow. 

To  separate  the  string  in  this  experiment  even  the  pressure  of  a  knife  blade  is  in- 

sulBcient ;  for  a  heavy  pressure,  as  manifested  by  the  bending  of  the  string,  is  borne 

before  separation   takes  place.     It 

may  be  taken  for  granted  that  in 

thus  severing  the  string,  the  power 

expended  has  been  employed  in  two 

ways ;  first  in  bending  the  string  ; 

second   in   separating    it.      If   the 

string  be  supported  and  prevented 

from  bending,  and  the  same  cutting 

edge  be  applied,  and  the  power  be 

measured  by  weights  or  a  spring 

balance,  it  will  be  seen  how  much 

of  the  former  was  expended  in  the 

useless  act  of  bending  the  string, 

and    therefore    quite    lost    in    the 

separating  of  it. 

If  the  cutting  instrument  were 
a  short  narrow  edge,  or  almost  a  sharpened  point,  and  drawn  forward,  each  fibre  would 
be  partially  cut.  A  repetition  of  this  action  in  the  same  line  would  still  further  deepen 
the  cut.  But  a  cutting  edge  requires  support  from  a  back,  i.e.  from  the  thicknessing 
of  the  metal,  otherwise  it  would  yield.  Further,  a  cutting  edge  held  at  right  angles 
to  the  surface  of  the  fibres  may  not  be  the  most  effective  position.  Let  any  one  draw 
the  point  of  a  knife  across  the  grain  of  a  smooth  pine  plank,  holding  the  blade  first  at 
right  angles  to  the  surface,  and,  secondly,  inclining  forward,  he  will  observe  that  by 
the  first  operation  the  fibres  are  roughly  scratched ;  by  the  second  they  arc  smootlily 
divided. 

Hence,  even  where  the  edge  has  deepened,  this  back  support  or  metal  strengthen- 
ing must  follow.  It  cannot  do  so  upon  this  knife  contrivance,  because  the  sharp  edge 
has  not  prepared  a  broad  way  for  the  thick  back,  which  being  of  a  wedge-like  character 
should  be  acted  upon  by  impact  and  not  by  such  tension  or  thrust  as  in  this  case  is  only 
available.  Therefore  simple  cutting  is  insufficient  for  the  purpose  of  separating  the 
fibres,  but  it  has  been  suggestive. 

If  now  something  must  enter  the  cut  thicker  than  the  edge,  then  it  is  clear  that  the 
edge  alone  is  insufficient  for  the  required  purpose,  and  an  edge,  as  a  cutting  edge  alone, 
cannot  bo  used  for  the  separation  of  the  fibres  cross-wise.  Longitudinally  it  may  be, 
and  is  used,  but  in  reality  what  appears  to  be  thus  used  is  a  wedge,  and  not  a  cutting 
edge,  for  in  a  true  cut  the  draw  principle  must  enter.  The  axe  and  chisel  do  not  work 
upon  the  cutting  "  edge,"  but  upon  the  driven  "  wedge "  principle.  They  are  driven 
by  impact,  and  not  drawn  by  tension  or  thrust  by  pressure. 

The  consideration  now  suggested  is  not  simply  how  to  cross-cut  the  fibres,  but, 
further,  how  to  permit  the  material  on  which  the  edge  ic  formed  to  follow  without 
involving  an  inadmissible  wedge  action.  It  may  be  done  as  in  a  class  of  saws  called 
metal  saws,  viz.  making  the  "edge"  the  thickest  part  of  the  metal  of  the  saw.  Tiiis 
however,  ignores  the  true  principle  of  the  saw,  and  introduces  the  file.    It  may,  in 


200  Caepentry — Easping  Tools. 

passing,  be  well  to  remark  that  in  marble  cutting,  where  the  apparent  saw  is  only  a 
blade  of  metal  without  teeth,  this  want  of  metal  teeth  is  supplied  by  sharp  sand,  each 
grain  of  which  becomes  in  turn  a  tooth,  all  acting  in  the  manner  of  a  file,  and  not  a  saw 
proper.  A  former  method  of  cutting  diamonds  was  similar  to  this.  Two  thin  iron 
wires  were  twisted,  and  formed  the  string  of  a  bow.  These  were  used  as  a  saw,  the 
movable  teeth  being  formed  of  diamond  dust.  A  similar  remark  applies  to  a  butcher's 
saw  ;  its  metal  teeth  really  act  as  files. 

For  the  purpose  of  separating  a  bundle  of  fibres,  the  "edge"  cannot  be  the  edge 
with  which  we  are  familiar  in  axes  and  chisels.  Such  an  edge  drawn  across  will  cut 
fibres  on  a  surface  only ;  this  is  insufficient,  for  a  saw  is  required  to  cut  fibres  below  a 
surface. 

The  tearing  also  of  upper  fibres  from  lower  ones  is  not  consistent  with  true  work. 
To  actually  cut  or  separate  these  is  the  question  to  be  considered,  and  the  simple  answer 
is  another  question.  Can  a  narrow  chisel  be  introduced  which  shall  remove  the  piece 
of  fibre  whose  continuity  has  been  destroyed  by  cutting  edges  previously  alluded  to  ? 
If  so,  then  an  opening  or  way  will  have  been  found  along  which  the  back  or  strengthen- 
ing part  of  the  cutting  edge  can  be  moved.  If,  however,  we  look  at  the  work  of  a 
single  cutting  edge,  we  notice  that,  although  the  continuity  of  the  fibre  is  destroyed,  yet 
the  separated  ends  are  still  interlaced  amongst  the  other  fibres.  To  obtain  a  piece 
removable  as  by  a  small  narrow  chisel,  it  will  be  requisite  to  make  a  second  cut 
parallel  to  the  first.  This  being  done,  there  is  the  short  piece,  retained  in  i^sition 
by  adhesion  only,  which  must  by  some  contrivance  be  removed,  for  it  is  in  the  way, 
and  the  room  it  occupies  is  that  in  which  the  back  of  the  cutting  edge  must  move.  To 
slide,  as  it  were,  a  narrow  chisel  along  and  cut  it  out  is  more  simple  in  suggestion  than 
in  execution. 

There  is  another  defect  upon  the  application  of  what  at  first  seems  sufficient  in 
principle,  but  only  wanting  in  physical  strength — it  is  the  absence  of  any  guide.  To 
draw  a  pointed  cutting  edge  along  the  same  deepening  line  needs  a  very  steady  hand 
and  eye.  This  consideration  of  the  problem  requires  that  some  guide  principle  must 
enter. 

To  increase  the  number  of  cutting  edges,  and  form  as  it  were  a  linear  sequence  of 
them,  may  give  a  partial  guidance,  and  if  the  introduction  of  our  chisel  suggestion  be 
imi^racticable,  then  another  device  must  be  sought.  Instead  of  the  2  parallel  cutters, 
it  will  be  possible  to  make  these  externally  parallel  but  internally  oblique  to  the  line  of 
cut,  in  other  words  to  sharpen  them  as  an  adze  is  sharpened  and  not  as  an  axe,  and  in 
doing  so  one  obstacle  will  be  removed,  it  is  true,  but  a  blemish  which  was  non-existent 
will  appear.  The  combining  obliquity  of  the  dividing  edges  will  so  press  upon  the 
intervening  piece  of  fibre  as  to  press  it  downwards  into  and  upon  the  lower  fibres,  thus 
solidifying,  and,  in  so  far  as  this  is  done,  increasing  the  difficulty  of  progressing  through 
the  timber. 

Note  the  mode  of  operating,  as  shown  by  Fig.  298.     The  portions  of  wood  ah  d  and 
ecd  have  been  removed  by  the  gradual  penetration  of  the  oblique  arms — not  only  have 
they  been  cut,  but  they  have  been  carried  forward  and  backward  and 
removed,  leaving  a  clear  space  behind  them  of  the  width  a  e.      But  how  293. 

with  regard  to  the   portion  within  the  oblique  arms  ?     That  part  would  ^ 

either  be  left  as  an  impeding  hillock,  or  it  would  have  to  be  removed  by  j 

the  introduction  of  such  a  plan  as  making  rough  the  insides  of  these 
oblique  arms.  If  we  consider  the  nature  of  the  material  left,  it  will  be 
admitted  to  consist  of  parlicles  of  woody  fibre  adhering  to  each  other 
only  by  the  glutinous  or  gummy  matter  of  the  timber,  and  not  cohering. 
If  the  breadth  a  e  is  not  too  large,  the  whole  of  the  heap  would  be  rubbed  away  by  the 
power  exerted  by  the  workman.  There  will  therefore  be  not  only  economy  in  power,  but 
economy  also  in  material  in  narrowing  a  e.   If  attention  be  given  to  the  form  of  the  pieces 


,    3 

lA 


■<z/ 


Caepentry — Easping  Tools.  201 

bent  from  the  plane  of  the  metal  of  which  this  cutting  instrument  is  made,  it  will  be 
observed  that  the  active  portion  has  3  edges,  of  which  the  lower  or  horizontal  one  only  is 
operative,  for  the  tool  rides  upon  the  fibres,  divides  them,  and  when  the  dividing  has 
been  accomplished,  the  sloping  parts  will  remove  the  hillock.  To  act  thus,  the  lower  edges 
would  require  to  be  sharpened  at  a  and  e  so  as  to  clear  a  gate  for  the  metal  to  follow. 
The  action  of  the  tool  as  described  would  require  a  downward  pressure,  in  order  to  cause 
the  cutting  segments  to  penetrate  vertically.  The  resistance  to  this  downward  entrance 
is  the  breadth  of  the  "  tooth,"  for  it  rides  upon  a  number  of  fibres  and  divides  them  by 
sliding  over  ;  the  complete  action  requires  not  only  downward  pressure  for  the  cut,  but 
also  horizontal  pressure  for  the  motion,  the  latter  both  in  the  advance  and  withdrawal 
of  the  tool.  These  2  pressures  being  at  right  angles  do  not  aid  each  other,  and  will 
employ  both  hands  of  the  workman.  It  is  very  obvious  that  the  compounding  of  these 
will  give  freedom  to  at  least  one  hand. 

For  the  jiresent,  assume  that  the  2  pressures  to  be  compounded  are  equal,  then  the 
simple  operation  is  to  employ  one  pressure  making  (say)  an  angle  of  45°  with  the 
horizontal  line  of  thrust.  Although  this  be  done,  yet  if  the  saws  be  any  length,  clearly 
the  angle  will  vary,  and  therefore  the  etFtct  of  the  sawyer's  labour  will  be  counteracted, 
either  as  a  consequence  of  excessive  thrust  or  of  excessive  pressure  at  the  beginning  or 
ending  of  the  stroke.  In  fact,  not  only  the  position  in  which  the  handle  is  fixed 
on  the  saw,  but  the  very  handling  itself  will  require  those  adaptations  which  experience 
alone  can  give. 

The  effect  of  this  will  be  to  cause  the  forward  points  to  penetrate,  and  cross-cut  the 
fibres  obliquely.  The  return  action  will  be  altogether  lost  unless  the  instrument  is 
arranged  accordingly,  and  sloped  in  the  other  direction. 

If  the  tool  becomes  a  single-handed  one,  and  relies  for  its  operation  upon  thrust  or 
tension  in  one  direction  only  (say  thrust),  then  cutting  edges  on  the  back  portions  of  the 
teeth  are  useless,  and  had  better  be  removed. 

The  experiment  worthy  of  trial  is,  can  tlie  whole  power,  or  nearly  the  whole  power, 
be  converted  into  a  tension  or  thrust  for  cutting  purposes.  To  do  this  the  cutting  edge 
must  be  so  formed  as  to  be  almost  self-penetrating ;  then  the  cutting  edge  is  no  longer 
a  horizontal  edge,  but  it  becomes  oblique,  on  the  advancing  face,  and  formed  thus  there 
is  no  reason  why  it  should  not  also  be  oblique  on  the  back  face,  and  so  cut  equally  in 
both  directions.  The  inclination  of  these  faces  to  the  path  of  the  saw  must  be  determined 
by  the  power — whether  it  is  capable  of  separating  as  many  fibres  as  the  teeth  ride 
between,  and  if  these  are  formed  to  cut  each  way  (as  a  single-handed  tool)  whether  it 
could  be  done ;  because  it  necessitates  a  construction  to  which  tension  and  thrust  may 
be  alternately  applied.  The  nature  of  the  wood,  the  power  and  skill  of  the  workman, 
and  the  strength  of  the  metal,  must  answer  this  suggestion. 

The  depth,  or  rather  length,  of  the  cutting  face  may  be  decreased,  and  the  number 
of  teeth  increased,  for  the  fibres  to  be  cut  cannot  be  more  vertically  than  can  be  contaiued 
between  2  teeth.  The  operative  length  of  the  tool  must  also  be  taken  into  account,  for 
the  combined  resistance  of  all  the  fibres  resting  within  the  teeth  must  be  less  than  the 
power  of  the  workman.  It  may  be  well  to  remark  that  this  difficulty  is  generally  met 
in  practice  by  the  workman  so  raising  certain  teeth  out  of  cut  as  to  leave  only  so  many 
in  operation  as  the  circumstances  enable  him  to  work.  One  advantage  results  by  so 
doing— the  guide  principle  of  a  longer  blade  is  gained  than  could  be  done  had  the  length 
been  limited  by  that  of  the  operating  teeth,  or  had  there  been  a  prolongation  of  metal 
without  any  teeth  upon  it.  To  avoid  complicating  an  attempt  to  deal  progressively  with 
the  action  of  the  saw,  this,  and  perhaps  other  considerations  may  for  a  while  pass  from 
notice.  Considered  as  hitherto  the  teeth  and  tool  are  planned  for  operation  in  both 
tension  and  thrust.  Now  these  are  of  so  opposite  a  nature  that  a  tool  perfect  under  the 
one  is  likely  to  be  imperfect  under  the  other.  "When  the  necessary  thinness  of  the 
material  and  the  tenacity  of  it  are  taken  into  account,  tension  seems  the  most  suitable  ; 


202  Caepentkt — Easping  Tools. 

but  although  the  ancients  and  the  •workmen  in  Asia  are  of  this-  way  of  thinking,  yet  in 
England  the  opposite  practice  is  adopted.  It  may  be  well  to  give  a  few  minutes  to  this 
branch  of  the  subject. 

The  form  of  a  saw  must  in  one  dimension  at  least  be  very  thin,  and  that  without  any 
opportunity  for  strengthening  any  part  by  means  of  ribs.  Wlien  a  strengthening  bar  is 
introduced  at  the  back  as  in  dovetail  saws,  the  depth  of  cut  is  limited.  In  order, 
then,  to  permit  the  guide  principle  to  operate  eflSoiently,  this  thin  material  must  be 
so  i^rolonged  as  under  all  circinnstances  to  guide  the  cutting  edge  in  a  straight  line. 
Of  course  we  arc  dealing  with  saws  to  be  used  by  hand,  and  not  with  ribbon  or 
machine-driven  saws. 

If  a  light  saw  blade  be  hooked  on  an  object,  or  placed  against  one,  then  tension 
causes  this  straight  blade  to  be  more  and  more  straightened.  On  the  contrary,  if  pressed 
forward  by  thrust,  the  weakness  of  the  blade  is  evidenced  by  the  bending.  Now,  formed 
as  saw  teeth  are,  either  to  cut  in  both  directions,  or  in  tlie  forward  direction  only, 
then  there  is  always  one  direction  in  which  the  work  to  be  done  is  accomplished  by  a 
thrust  upon  this  thin  metal.  Clearly  the  metal  will  bend.  If,  however,  the  teeth  are 
such  as  to  cut  in  one  direction  only,  and  tliat  when  the  tension  is  on  the  metal,  the  work 
tends  to  preserve  that  straightness  of  blade  upon  which  an  important  quality  and  use  of 
the  tool  depends.  That  this  tension  system  can  be  efficient  with  a  very  narrow  blade  is 
clear  from  the  extensive  use  of  ribbon  saws.  There  is,  however,  a  property  in  the 
breadth  of  the  blade  which  applies  equally  to  the  tension  and  thrust  systems — it  is  the 
guide  principle.  The  breadth  of  the  blade  operates  by  touching  the  sides  of  the  gate- 
way opened  by  the  teeth.  When  it  is  desired  to  dispense  with  a  straight  guide  for 
sawing  purposes,  it  is  done  by  narrowing  the  blade  as  in  lock  saws,  tension  frame 
saws,  &c. 

There  is  obviously  a  limit  to  the  required  breadth  even  for  the  most  effectual  guid- 
ance and  movement :  this  guidance  should  be  uniform  through  the  entire  cut ;  hence 
upon  the  guide  princijjle  alone,  there  is  required  a  breadth  of  saw  beyond  what  is 
requisite  for  the  teeth.  The  reasoning  hitherto  has  landed  us  upon  a  parallel  blade  of 
some  (as  yet)  undecided  breadth.  When  one  of  our  ordinary  hand  cross-cutting  saws  is 
examined,  it  is  observed  to  be  taper  and  not  parallel,  the  tapering  being  at  the  edge  or 
back,  where  the  teeth  are  not.  This  has  been  done  to  meet  our  practice  of  using  the  saw 
as  an  instrument  for  thrust  instead  of  tension.  When  the  teeth  near  the  end  farthest 
from  the  handle  are  to  operate,  and  there  is  no  steadiness  obtained  from  the  guidance  of 
the  sides  of  the  already  separated  timber,  then  the  whole  of  the  thrust  must  be 
transmitted  through  the  necessarily  thin  blade.  An  attempt  to  compensate  for  this  thin- 
ness by  increasing  the  breadth  is  the  only  course  open.  It  is  one  not  defensible  upon 
any  true  principles  of  constructive  mechanism,  for  it  is  not  in  the  increased  breadth  or 
extension  of  surface  that  resistance  to  bending  is  wanted,  but  it  is  in  the  thickness,  and 
that  is  impracticable. 

In  thrust  saws,  the  hand  and  the  arm  of  the  workman  occupy  a  definite  position,  and 
the  line  of  pressure  on  the  saw  is  thus  very  much  determined  by  the  inclination  of  the 
handle  (that  part  grasped  in  the  hand)  to  the  line  of  teeth  prolonged  backwards.  If  the 
handle  be  placed  at  such  an  angle  that  a  large  part  of  the  resolved  thrust  be  perpendi- 
cular to  the  line  of  teeth,  then  the  "  bite  "  may  be  greater  than  the  other  resolved  portion 
of  the  power  can  overcome.  At  another  angle  the  "bite"  may  be  very  little,  and 
althougli  the  saw  thus  constructed  would  move  easily,  it  would  work  "  sweetly,"  but 
slowly.  The  construction  is  suitable  for  saws  with  fine  teeth  and  for  clear  cuttings.  It 
will  be  seen  from  these  considerations  that  there  should  be  preserved  a  very  carefully 
considered  relationship  between  the  size  and  angle  of  the  teeth  and  the  position  in  which 
the  handle  is  fixed,  or  rather  the  varyingadaptability  of  the  workman's  thrust.  Indeed, 
upon  fully  developed  and  accurate  principles,  the  timber  to  be  cut  should  first  be 
examined,  its  fibrous  texture  determined  physically,  and  a  saw  deduced  from  these  data» 


Caepentky — Rasping  Tools.  203 

having  teeth  and  handle  so  related  as  to  do  the  required  work  with  a  minimum  of  power. 
This  multiplicity  of  saws  is  not  available ;  and  as  in  music  the  multiplicity  of  notes 
which  only  the  violin  can  produce  are  rtyected  in  other  instruments,  so  here  the  multi- 
plicity of  theoretical  saws  is  rejected,  and  a  kind  of  rough  and  ready  compromise  is 
eflfected  between  the  position  of  the  handle  and  the  angle  and  depths  of  the  teeth.  It 
would,  however,  well  repay  those  whose  works  are  usually  of  the  same  character  and  of 
the  same  class  of  timber,  to  consider  these  points,  witli  a  view  to  the  selection  of  saws 
and  position  of  handle  suitably  constructed  to  do  the  work  with  the  least  expenditure  of 
power. 

A  few  words  upon  the  handles  of  single-handed  saws.  Whatever  may  be  the  other 
conditions  required  in  handles,  the  large  majority  of  saw-handles  have  the  curved  hooked 
projections  a  and  b.  Fig.  299;  these  are  connected  with  the  pressure  of  the  sawyer  on  the 
teeth.  If,  in  sawing,  the  hand  bears  upon  the  upper  hook  a,  then  an  increased  pressure 
is  given  to  the  forward  teeth ;  if  upon  the  hook  b,  the  pressure  on 
the  forward  teeth  is  released,  and  consequent  ease  in  sawing  results,  ~^^' 

also  a  pressure  may  be  given  to  the  back  teeth.  The  angle  at 
which  direct  thrust  ought  to  act  upon  the  line  of  teeth  in  tlie  saws 
is  obviously  very  different.  Each  material  may  be  said  to  have 
its  own  proi^er  angle.  Provision  may  be  made  by  2  set  screws 
above  a  and  6  for  varying  the  intersection  of  the  line  of  thrust  with 
the  line  of  teeth.  It  will  be  further  noticed  that  in  the  handle  of 
the  "  one-man  saw,"  Fig.  301,  the  upper  hook  is  wanting,  and  this 
because  under  any  circumstances  the  weight  of  the  saw  is  more 
than  sufficient,  and  therefore  it  is  not  requisite  that  any  resolved  portion  of  the  work- 
man's energy  should  be  compounded  with  this.  Not  so  with  the  other  hook  ;  that  is 
retained  in  order  that  thus  the  weight  of  the  saw  may  be  taken  from  the  work.  For 
these  reasons  the  line  of  direct  thrust  is  nearly  parallel  with  that  of  the  teeth.  We 
seem  to  be  guilty  of  much  inconsistency  in  the  placing  as  well  as  in  the  formation  of 
saw  handles. 

A  brief  recapitulation  of  what  has  been  said  may  suitably  close  this  far  from 
exhausted  branch  of  the  subject. 

There  have  been  considered  : — 

The  effect;  of  impact  transverse  to  fibre. 

The  efiect  of  thrust  transverse  to  fibre. 

The  passing  of  a  cutting  edge  transverse  to  fibre. 

The  reduction  of  length  of  cutting  edge  transverse  to  fibre. 

The  introduction  of  combined  vertical  with  horizontal  cut. 

The  rounding  off  the  back  of  cutting  edge. 

The  pressures  required  in  sawing. 

Tension  compared  with  thrust. 

The  angular  position  of  handle. 

The  resolution  of  forces  operating. 

Now  may  be  considered  the  circumstances  which  influence  the  form  and  position  both 
of  the  teetli  and  the  edges  to  be  put  upon  them,  in  the  case  of  hand-saws  operating 
either  by  thrust  alone,  or  by  thrust  and  tension  combined  (as  in  the  2-handled  cross- 
cutting  saws  used  by  2  men,  or  in  the  whip  and  frame  saw  used  in  saw  pits).  Unless 
specially  mentioned  the  thrust  hand-saw  for  cross-cutting  will  be  the  only  one 
considered. 

It  may  be  well  at  the  outset  to  explain  that  the  coarseness  and  fineness  of  saw» 
are  estimated  by  the  number  of  teeth  points  in  an  inch.  The  sawmaker  uses  the 
term  "  pitch,"  but  not  in  the  sense  as  employed  in  wheels  and  screws.  By  pitch  he 
"  means  the  inclination  of  the  face  of  the  teeth  up  which  the  shaving  ascends."  Clearly 
if  the  saw  is  to  cut  when  drawn  in  both  du-ections,  the  slope  of  the  teeth  from  the  points 


204  Carpentky — Easping  Tools. 

must  be  the  same  on  both  sides ;  indeed,  tliis  may  be  considered  the  primitive  form  of 
saw  teeth,  and  derived  as  the  saw  is  said  to  have  been  from  the  backbone  of  a  fish,  it  is 
tlie  form  that  would  be  suggested.  To  use  a  saw  with  such  teeth  in  the  most  perfec/' 
manner  would  require  that  the  action  at  each  end  sliould  be  the  same ;  hence,  tliese  are 
the  forms  of  teeth  generally  met  in  the  ordinary  2-handled  saw  used  for  the  cross-cutting 
of  timber.  The  teeth  of  these  saws  are  generally  wide  spaced,  and  the  angle  included  in 
their  point  is  from  40°  to  60°.  The  forms,  however,  of  teeth,  to  cut  in  both  directions, 
are  sometimes  more  varied,  especially  when  the  material  is  not  of  uniform  non-fibrous 
character.  When  this  equality  of  tension  in  both  directions  cannot  be  had,  and  the 
workman  is  required  to  cross-cut  the  timber  by  a  one-handled  saw,  it  is  clear  that  he 
must  consider  the  action  as  tliat  of  tension  or  thrust  alone— one  of  these  only.  The  sole 
reason  why  both  are  not  adoi^ted  seems  to  be  that  were  it  so,  very  different  muscular 
motions  and  postures  of  the  body  would  be  introduced,  and  probably  experience  has 
shown  that  these  are  more  fatiguing  than  the  alternate  pressure  and  relaxation  which 
takes  place  in  the  ordinary  process  of  hand-sawing.  Now,  if  the  cut  is  in  the  thrust 
only,  then  the  form  of  the  back  of  the  tooth  must  be  the  very  reverse  of  that  of  the  front, 
for  it  ought  to  slide  past  the  wood,  because  not  required  to  separate  the  fibres.  In  this 
case  the  back  of  the  tooth  may  be  sloped  away,  or  it  may  be  shaped  otherwise.  The 
faces  of  the  teeth  are  no  longer  bound  to  be  formed  in  reference  to  an  equality  at  the 
back.  Indeed,  with  the  liberty  thus  accorded,  there  has  arisen  an  amount  of  fancy 
in  the  forms  of  teeth,  which  fancy  has  developed  into  prejudice  and  fashion.  Names 
dependent  either  upon  uses  or  forms  are  given  to  these,  and  they  are  distinguished  by 
such  names  in  the  trade.  Peg  tooth,  M  tooth,  half-moon  tooth,  gullet  tenth,  briar  tooth ; 
also  "  upright  pitch,"  "  flat  pitch,"  "  slight  pitch."  0^  these  varieties,  custom  has  selected 
for  most  general  use  in  England  the  one  in  which  the  face  of  the  tooth  is  at  right  angles 
to  the  line  of  the  teeth.  The  backs  of  the  teeth  are,  therefore,  sloped  according  to  the 
distance  between  the  teeth  and  the  coarseness  or  fineness  of  the  saw.  This  is  called 
ordinary,  or  hand-saw  pitch. 

A  consideration  of  the  action  of  the  saw  in  cross-cutting  timber  settles  the  cutting 
■edge,  and  so  suggests  the  mode  of  sharpening.  Taking  our  ordinary  cross-cutting 
single-handed  saw  as  the  type,  the  forward  thrust  is  intended  to  separate  the  fibres,  and 
this  not  in  the  way  of  driving  a  wedge,  but  in  the  actual  removal  of  a  small  piece  by  two 
parallel  cuts.  For  example,  if  O  O.  Fig.  300,  be  a  fibre,  then  the  action  of  the  saw  must 
be  to  cut  clean  out  the  piece  a,  h,  so  making  a  space  a,  h,  wider  than  the  steel  of  which  the 
saw  is  made.  The  cleaner  the  cuts  a  d,hc  are  the  better. 
Now  this  clean  cut  is  to  be  made  by  the  teeth  advancing  300. 

toward  the  fibre.     If  they  come  on  in  axe  fashion,  then    rt^         t> 

the  separation  is  accomplished  by  the  direct  thrust  of  Cj I I £> 

a  sharp  edge,  in   fact,   by  a  direct  wedge-like   action.  *^ 

Now  a  wedge-like  action  may  be  the  best  for  separating 

fibre  adhering  to  fibre,  but  it  is  an  action  quite  out  of  place  in  the  cross-cutting  of  a 
single  fibre,  in  which  cohesion  has  to  be  destroyed.  There  is  needed  a  cutting  action, 
i.e.  a  drawing  of  an  edge,  however  sharp,  across  the  mark  for  separation;  this 
drawing  action  is  very  important.  Admit  for  the  present  that  such  action  is  essential, 
then  the  saw  tooth  as  constructed  does  not  supply  it.  Clearly  the  sharp  edge  must 
somehow  or  other  be  drawn  and  pressed  as  drawn  across  the  fibre.  Two  ways  of  accom- 
plishing this  present  themselves.  The  ofiect  on  the  action  of  the  workman  is  very 
different  in  these  cases.  In  the  first  we  must  press  the  saw  upon  the  fibre,  and  at; 
the  same  time  thrust  it  lengthwise.  Now  in  soft  timber,  and  with  a  saw  having  teeth 
only  moderately  sharp,  this  pressure  will  tend  rather  to  force  the  fibres  into  closer 
contact,  to  squeeze  them  amongst  each  other,  to  solidify  the  timber,  and  increase  the 
diflSculty  in  cutting.  Two  actions  are  here,  pressure  and  thrust.  In  the  second  case 
the  pressure  must  be  very  light  indeed ;  if  otherwise,  the  point  of  the  tooth  will  gather 


Cakpentry— Rasping  Tools.  205 

lip  more  fibres  than  the  strength  of  the  workman  can  separate ;  indeed,  as  a  rule,  in 
the  cross-cutting  of  broad  timber,  with  all  the  saw  teeth  in  action,  pressure  is  not 
required,  the  average  weight  of  the  saw-blade  sufficing  for  the  picking  up  of  the  fibres. 
It  is  probably  from  the  delicate  and  skilful  handling  which  a  tooth  thus  constructed 
requires,  that  hand-saws  are  not  more  generally  constructed  with  teeth  of  this  form. 
In  addition  to  these  there  is  the  penetrating  tooth,  as  the  points  of  the  peg  tooth 
and  others.  Whatever  may  be  the  form  of  the  teeth,  the  small  piece  ah,  cd,  Fig.  300, 
has  to  be  removed  so  as  to  leave  the  ends  from  which  it  is  taken  as  smooth  and 
clean  cut  as  possible,  therefore  the  cutting  edge  must  be  on  the  outside  of  the  tooth. 
This  being  so,  it  follows  that  the  act  of  severing  a  fibre  will  be  attended  with  com- 
pression whose  effect  is  to  shorten  it.  Thus  condensed  it  is  forced  up  into  the  space 
between  the  teeth.  If  now  this  space  is  not  so  formed  as  to  allow  the  condensed 
piece  to  drop  freely  away  so  soon  as  the  tooth  passes  from  the  timber,  then  the  saw  will 
become  choked,  and  its  proper  action  will  necessarily  cease.  In  large  saws  this  is 
provided  for  in  the  shape  of  the  "gums"  in  which  the  teeth  may  be  said  to  be  set. 
What  in  America  are  called  "  gums  "  are  frequently  in  England  called  "  throats." 
Saws  cannot  work  easily  unless  as  much  care  is  bestowed  upon  the  "  throats  "  or 
"  gums  "  as  is  given  to  the  teeth. 

Any  exhaustive  attempt  to  deal  with  the  considerations  which  present  themselves 
to  one  who  enters  upon  the  question,  what  under  all  the  varying  conditions  of  the 
problems  should  be  the  form  and  set  of  a  saw-tooth,  would  require  more  experimental 
knowledge  and  patient  research  than  the  subject  seems  to  have  received.  There  are 
more  than  100  different  forms  of  teeth.  Sheffield  and  London  do  not  agree  upon  the 
shape  of  the  handle.  The  Eastern  hemisphere  and  the  Western  do  not  agree  whether 
sawing  should  be  an  act  of  tension  or  one  of  thrust. 

The  quantity  of  timber  cut  down  in  America  must  have  led  to  investigations  with 
respect  to  saws  such  as  the  requirements  of  this  country  were  not  likely  to  call  forth. 
Hence  wo  have  very  much  to  learn  from  the  Americans  on  this  point. 

As  it  seems  most  judicious  to  investigate  the  principles  by  considering  a  large  and 
heavy  tool,  perhaps  it  may  be  well  to  examine  the  largest  handicraft  saw.  This  (Fig.  301)' 

301. 


J 


is  a  "one-man  saw"  4  ft.  long,  by  Disston,  Philadelphia.  Long  as  the  blade  is,  it  is 
not  too  long.  The  travel  is  near,  but  still,  within  the  limit  of  a  man's  arm.  To  enter 
the  wood,  the  teeth  at  the  extreme  end  are  used.  These  are  strong,  but  of  the  form 
generally  met  with  in  the  largest  of  our  own  cross-cut  saws.  The  acting  teeth  are  of 
an  M  shape,  with  a  gullet  or  space  between  them.  The  angle  at  Avhich  the  teeth  are 
sharpened  is  very  acute ;  the  consequence  of  this  and  of  their  form  is,  that  they  cut 
smoothly  as  a  sharp  knife  would  do;  indeed,  much  as  a  surgeon's  lancet  would. 
Some  teeth  are  formed  on  the  principle  of  the  surgeon's  lancet,  and  these  are  called 
"  fleam  "  teeth.  The  spaces  between  the  M's  in  the  "  one-man  saw"  are  "gums"  for 
the  reception  and  removal  of  the  pieces  cut  out  of  the  separated  fibre.  In  the  particular 
case  before  us,  the  M  is  f  in.  broad  and  f  in.  deep ;  the  upright  legs  of  the  M  are 
sharpened  from  within,  the  V  of  the  M  is  sharpened  on  both  sides.  The  legs  are  "  set" 
to  one  side  and  the  V  to  the  other  side.  Thus  arranged,  tlie  saw  cuts  equally  in  tension 
and  in  thrust,  and  the  debris  is  brought  out  freely  at  each  end.    The  M  tooth  for  this 


206 


Caepentry — Easping  Tools. 


302. 


Oy 


^^^f^n-r^^'^ 


double-cutting  results  from  an  observation  on  two  carefully-toothed  short  cross-cut 
elementary  saws,  where  it  will  be  noticed  that  the  form  of  tooth  to  cut  both  ways, 
resulting  from  the  combination,  is  M.  The  set  of  this  large  "  one-man  saw  "  is  worthy 
of  notice.  An  inspection  of  the  cutting  points  will  show  that  each  point  is  diverted 
from  the  plane  of  the  saw  blades  not  more  than  about  -J^  in.  When  the  object  of 
*'  set "  is  considered,  it  will  be  allowed  that  so  little  is  sufficient. 

The  annexed  diagrams  (Fig.  302)  of  teeth  of  certain  cross-cut  saws  used  in  America 
may  illustrate  tlie  present  subject.  A  single  tooth  will  in  some  instances  be  observed 
between  the  M  teeth:  this  is  a  "clearance"  tooth,  and  is  generally  shorter  than  the 
cutting  tooth.  Sometimes  it  is  hooked,  as  may  be  seen  in  c;  in  such  case  it  is  shorter 
by  -i-  in.  than  the  cutting  teeth,  and  acts  the 
part  of  a  plane  iron  by  cutting  out  the  pieces 
of  fibre  separated  by  the  other  or  cutting 
teeth,  which  cutting  teeth  under  these  cir- 
cumstances are  lancet-like  sharpened  to  very 
thin  edges. 

That  the  "  set "  of  the  teeth  should  be 
vmiform  in  the  length  of  the  saw  follows 
from  a  moment's  reflection  upon  the  object 
of  this  set.  If  one  tooth  projects  beyond  the 
line  of  the  otliers,  that  tooth  will  clearly 
scratch  the  wood,  and  therefore  leave  a 
roughness  on  the  plank.  As  more  than  its 
share  of  work  is  then  allotted  to  it,  the 
keenness  of  edge  soon  leaves  it,  and  thus 
increases  the  labour  of  the  sawyer.  The 
American  contrivance  for  securing  a  uni- 
formity in  the  set  of  the  teeth  is  the  "  side- 
file."  The  three  set  screws  determine  the 
elevation  of  the  file  above  the  face,  and  the 
travel  of  the  short  length  of  fine  cut  file 
reduces  all  excessive  "  sets "  to  a  uniform 
*'  set "  through  the  entire  length  of  the  saw. 

The  "  crotch  punch  "  is  also  an  American 
contrivance  for  obtaining  a  clearance  set  out  of  a  spreading  of  the  thick  steel  of  the  saw 
by  an  ingeniously  formed  angular  punch. 

It  is  occasionally  required  to  saw  certain  cuts  to  the  same  depth,  as,  for  instance,  in 
the  making  of  tenons.  The  saw  to  which  tlie  term  "  tenon  "  is  apphed  is  more  suited  for 
cabinet  than  for  carpenters'  work.  However,  an  ordinary  saw  may  be  provided  with 
a  gauge,  which  can  be  adjusted  so  as  to  secure  a  uniform  depth  in  any  number  of  cuts, 
and  in  this  respect  it  is  even  superior  to  a  tenon-saw,  and  may  be  suggestive  to  some 
whose  labours  might  be  facilitated  by  the  adoption  of  such  a  contrivance. 

The  rip-saw  considered  as  a  cutting  tool,  may  be  likened  to  a  compound  chisel,  and  the 
form  of  teeth  which  would  operate  with  the  least  application  of  power  would  be  the  same 
as  that  of  a  mortising  chisel ;  but  knots  and  hard  wood  are  conditions  which  call  for 
rigid  teetli,  rendering  the  chisel  form  impracticable,  except  for  sawing  clear  lumber,  and 
with  a  high  degree  of  skill  in  filing  and  setting.  The  limit  of  endurance  of  such  steel 
as  must  be  employed  for  saws,  will  not  admit  of  pointed  teetli ;  these  will  break  in 
cutting  through  knots  and  hard  wood,  and  no  form  of  saw-teeth  which  permits  their 
points  to  crumble  and  break  should  Ixj  adopted.  In  actual  practice,  with  the  skilled 
filer,  there  is  a  tendency  to  create  pointed  saw-teeth,  and  when  there  is  a  want  of  skill  in 
the  filer  the  tendency  is  the  other  way,  and  teeth  unnecessarily  blunt  are  common.  "  The 
action  of  a  saw  when  ripping  or  cutting  with  the  fibres  of  the  wood  is  entirely  different 


Carpentry— Easping  Tools.  207 

from  that  when  cross-cutting  or  severing  the  fibres  of  the  wood  transversely ;  the  shape 
of  the  teeth  and  the  method  of  sharjiening  should  therefore  differ.     In  the  case  of  a  rii)- 
saw,  the  action  of  the  saw  is  chiefly  splitting,  the  teeth  acting  like  a  scries  of  small 
wedges  driven  into  and  separating  the  longitudinal  fibres  of  the  wood ;  whilst  with  cross- 
cutting  saws,  the  fibre  of  the  wood  has  to  be  severed  across  the  grain  :  it  is  comparatively 
unyielding,  the  teeth  of  the  saw  meet  with  much  more  resistance,  and   it  is  found 
necessary  to  make  the  teeth  more  upright  and  more  acute  or  lancet-shaped  than  for 
cutting  with  the  grain.     The  faces  of  the  teeth  should  be  sharpened  to  a  keen  ed-e  and 
for  hard  wood  filed  well  buck,  so  that  in  work  they  may  have  a  direct  cutting  action 
similar  to  a  number  of  knives.     Care  should  also  be  taken  that  the  teeth  are  made  of 
sufficient  depth  to  afford  a  free  clearance  for  the  sawdust.     This  is  an  important  point 
too  with  rip-saws.      The  teeth  should  also  be  equal  in  kngth ;  if  not,  the  longest  teeth 
get  the  most  work,  and  the  cutting  power  of  the  saw  is  much  lessened.     The  length  of 
the  teeth  should  depend  on  the  nature  of  the  wood  being  sawn :  for  sawing  sappy  or 
fibrous  woods,  long,  sharp,  teeth  are  necessary,  arranged  with  ample  throat  space  for 
sawdust  clearance ;  care  must  be  taken,  however,  that  the  teeth  are  not  too  long,  or  they 
will  be  found  to  spring  and  buckle  in  work.     In  sawing  resinous  woods,  such  as  pitch 
pine,  the  teeth  of  the  saw  should  have  a  considerably  coarser  set  and  space  than  for  hard 
woods.     It  will  also  be  found  advisable— especially  with  circular  saws— to  lubricate  the 
blades  well,  as  the  resinous  matter  is  thus  more  easily  got  rid  of.     In  sawing  hard  woods, 
either  with  reciprocating  or  circular  saws,  the  feed  should  be  not  more  than  one-half  as 
fast  as  for  soft  wood,  the  saw  should  contain  more  teeth,  which  should  be  made  consider- 
ably shorter  than  those  used  for  soft  wood,  roughly  speaking,  about  J  ;   it  is  impossible, 
however,  to  make  a  fixed  rule,  owing  to  the  great  variety  of  woods  and  their  difterent 
hardnesses ;  the  length  of  teeth  which  may  be  found  to  suit  one  wood  well  may  in 
another  case  require  to  be  increased  or  decreased.      In  cutting  woods  which  are  much 
given  to  hang  and  clog  the  saw-teeth,  increment  teeth  may  be  used  with  advantage  ; 
these  are  arranged  with  fine  teeth  at  the  point  of  the  saw,  wliich  gradually  get  coarser 
till  the  heel  of  the  saw  is  reached  ;  thus  the  fine  teeth  commence  the  cut  and  the  coarser 
ones  finish  it,  obviating  in  a  great  degree  the  splintering  and  tearing  of  the  wood  caused 
by  coarse  teeth  striking  the  wood  at  the  commencement  of  the  cut.  As  regards  the  angles 
of  the  teeth  best  adapted  for  cutting  soft  or  hard  woods  no  absolute  rule  can  be  laid 
down.     The  following  may  be  modified  according  to  circumstances.     If  a  line  be  drawn 
through  the  points  of  the  teeth,  the  angle  formed  by  the  fiice  of  the  tooth  with  this  line 
should  be  :  For  cutting  soft  woods,  about  65°-70° ;  for  cutting  hard  wood,  about  80°-85°. 
The  angle  formed  by  the  face  and  top  of  the  tooth  should  be  about  45°-50°for  soft  wood, 
and  65°-70°  for  hard.     The  angle  of  the  tooth  found  best  for  cutting  soft  woods  is  much 
more  acute  than  for  hard.     Terms  used  in  describing  the  parts  of  a  saw  are : — "  Space  "  : 
the  distance  from  tooth  to  tooth  measured  at  the  points.  "  Pitch  "  or  "  rate  "  :  the  angle  of 
the  face  of  the  tooth  up  which  the  shaving  ascends,  and  not  the  interval  between  the 
teeth,  as  with  the  threads  of  a  screw.     "Gullet"  or  "  throat"  :  the  depth  of  the  tootli 
from  the  point  to  the  root.     "  Gauge  "  :  the  thickness  of  the  saw,  generally  measured  by 
the  wire  gauge.     "Set":  the  amount  of  inclination  given  to  the  saw-teeth  in  either 
direction  to  effect  a  clearance  of  the  sawdust.    "  Points  "  :  small  teeth  are  reckoned  by 
the  number  of  teeth   points  to    the   inch.     The  chief  facts  to  be  borne  in   mind  in 
selecting  a  saw  with  the  teeth  best  suited  to  the  work  in  hand  are  the  nature  and  con- 
dition of  the  wood  to  be  operated  on.     No  fixed  rule  can,  however,  be  laid  down,  and  the 
user  must  be  guided  by  circumstances.     All  saws  should  be  ground  thinner  towards  the 
back,   as   less   set    is   thus   necessary,  the  friction  on  the  blade  is  reduced,  and  the 
clearance  for  sawdust  is  improved.     Care  should  also  be  taken  that  they  are  perfectly 
true  and  uniform  in  toothing  and  temper.    The  angle  of  the  point  of  a  tooth  can  be 
found  by  subtracting  its  back  angle  from  its  front,  and  to  do  the  best  and  cleanest  work 
this  angle  should  be  uniform  in  all  the  teeth  of  the  saw."    (M.  Powis  Bale,  M.I.M.E., 
A.M.I.C.E.) 


208 


Carpentry — Easping  Tools. 


The  following  table  includes  saws  generally  used  by  mecliauic3  who  work  wood  by 
hand : — 


Names. 


Without  Bachs. 

Rip-saw       

Fine  rip-saw 

Haud-saw 

Cut-off  saw 

Panel-saw 

Fiue  panel-saw  .. 

Siding-saw 

Table-saw 

Compass  or  lock-saw 
Keyhole  or  pad-saw  . . 

With  Backs. 

Tenon-saw 

Sash-saw     

Carcass-saw 
Dovetail-saw 


Length 

in 
Inches. 


Breadth  in  Inches. 


At  Handle.  1     At  End. 


Thickness 

in 

Inches. 


Teeth  to 

the 

Inch. 


28-30 
26-28 
22-24 
22-24 
20-24 
20-24 
10-20 
18-26 
8-18 
6-12 


16-20 

14-16 

10-14 

6-10 


7  -9 
6  -8 
5  -Ih 
5  -ll 

H-n 

4  -6 

2i-3^ 
13-91 

1  -u 


3  -4 

3  -3J 

21-3 

2i-3 

2'-2i 

2  -Ih 

11-2" 

1  -n 

1_     3 

i-    1 

8        4 


3J-41 
2i-3i 
2  -3 
U-2 


0-05 

0-042 

0-042 

0-042 

0-042 

0-035 

0-032 


0-032 
0-0-28 
0-025 
0-022 


31 

4 
5 
6 

7 

8 

6-12 

7-8 
8-9 
9-10 


10 
11 

12 
14-18 


(Holtzapfel.) 

Qualities. — Hodgson  made  a  number  of  experiments  on  saws  to  test  their  qualities 
and  capabilities  ;  and  after  using  them  in  various  ways,  fairly  and  unfairly,  he  arrived 
at  the  following  conclusions  : — 

(1)  That  a  saw  with  a  thick  blade  is,  9  cases  out  of  10,  of  a  very  inferior  quality,  and 
is  more  apt  to  break  than  a  thin-bladed  saw ;  it  requires  more  "set,"  will  not  stand  an 
edge  nearly  so  long  as  a  thin  one,  is  more  difficult  to  file,  and  being  heavier  and  cutting 
a  wider  kerf,  is  more  tiresome  to  use. 

(2)  Saws  hung  in  plain  beech  handles,  with  the  rivets  flush  or  countersunk,  are 
lighter,  easier  to  handle,  less  liable  to  receive  injury,  occupy  less  space  in  the  tool  chest, 
and  can  be  placed  with  other  saws  without  dulling  the  teeth  of  the  latter  by  abrasion 
on  the  rivets. 

(3)  Blades  that  are  dark  in  colour,  and  that  have  a  clear  bell-like  ring  when  struck 
with  tlie  ball  of  the  finger,  appear  to  be  made  of  better  stuff  than  those  having  a  light 
iron-grey  colour ;  and  he  noticed,  in  proof  of  this,  that  the  thinner  the  blades  were,  the 
darker  the  colour  was,  and  that  saws  of  this  description  were  less  liable  to  "  buckle  "  or 
"  twist." 

(4)  American-made  saws,  as  a  rule,  are  better  "  hung "  than  English  ones.  And, 
■where  beech  is  used  for  handles,  and  the  rivets  are  flush  or  countersimk,  all  other 
things  being  equal,  the  American  make  is  the  most  desirable. 

(5)  Polished  blades,  although  mechanics  have  a  strong  prejudice  against  them,  cut 
freer  and  much  easier  than  blades  left  in  the  rough,  and  they  are  less  liable  to  rust. 

(G)  Saws  that  ring  clear  and  without  tremor,  when  held  by  the  handle  in  one  hand 
and  struck  on  the  point  with  the  other  hand  and  held  over  at  a  curve,  will  be  found  to 
be  well  and  securely  handled ;  but  saws  that  tremble  or  jar  in  the  handle,  when  struck 
on  tlie  point  of  the  blade,  will  never  give  satisfaction. 

Selecting. — The  following  valuable  suggestions  on  the  purchasing  of  saws  are  given 
by  Disston,  the  well-known  saw-maker  of  Philadelphia.  The  first  point  to  be  observed 
in  the  selection  of  a  hand-saw  is  to  see  that  it  "  hangs  "  right.  Grasp  it  by  the  handle 
and  hold  it  in  position  for  working.    Then  try  if  the  handle  fits  the  hand  properly^ 


Carpentry — Kasping  Tools.  209 

These  are  points  of  great  importance.  A  handle  ought  to  be  symmetrical,  and  aa 
handsome  as  a  beautiful  picture.  Many  handles  are  made  out  of  green  wood ;  they  soon 
shrink  and  become  loose,  the  screws  standing  above  the  wood.  An  unseasoned  liandlu 
is  liable  to  warp  and  throw  the  saw  out  of  truth.  The  next  thing  in  order  is  to  try  the 
blade  by  springing  it.  Then  see  that  it  bends  regular  and  even  from  point  to  butt  in 
proportion  as  the  width  of  the  saw  varies.  If  the  blade  bo  too  heavy  in  comparison  to 
the  teeth  the  saw  will  never  give  satisfaction,  because  it  will  require  twice  the  labour  to 
use  it.  The  thinner  j'ou  can  get  a  stiff  saw  the  better.  It  makes  less  kerf,  and  takes 
less  muscle  to  drive  it.  A  narrow  true  saw  is  better  than  a  wide  true  saw ;  there  is  less 
danger  of  dragging  or  creating  friction.  You  will  get  a  smaller  portion  of  saw-blade, 
but  you  will  save  100  dollars'  worth  of  muscle  and  manual  labour  before  the  saw  is  worn 
out.  Always  try  a  saw  before  you  buy  it.  See  that  it  is  well  set  and  sharpened,  and 
has  a  good  crowning  breast ;  place  it  at  a  distance  from  you,  and  get  a  proper  light  to 
strike  on  it,  and  you  can  see  if  there  be  any  imperfections  in  grinding  or  hammering. 
We  set  our  saws  on  a  stake  or  small  anvil  with  one  blow  of  a  hammer.  This  is  a  severe 
test,  and  no  tooth  ought  to  break  afterwards  in  setting,  nor  will  it,  if  the  mechanic 
adopts  the  proper  method.  The  saw  that  is  easily  filed  aud  set  is  easily  made  dull.  We 
have  frequent  complaints  about  hard  saws,  but  they  are  not  as  hard  as  we  would  make 
them  if  we  dared;  but  we  shall  never  be  able  to  introduce  a  harder  saw  until  the 
mechanic  is  educated  to  a  more  correct  method  of  setting  his  saw.  The  principal  point 
is  that  he  tries  to  get  part  of  the  set  out  of  the  body  of  the  plate  when  the  whole  of  the 
set  must  be  got  out  of  the  tooth.  As  soon  as  he  gets  below  the  root  of  the  tooth  to  get 
his  set,  he  distorts  and  strains  the  saw-plate.  Tliis  will  cause  a  full-tempered  cast-steel 
blade  to  crack,  and  the  saw  will  eventually  break  at  this  spot. 

Grimshaw  says  that  a  hand-saw  must  be  springy  and  elastic,  with  almost  a  "  Toledo 
blade  "  temper.  There  is  no  economy  in  buying  a  soft  saw ;  it  costs  more  in  a  year  for 
files  and  filing  than  a  hard  one  does,  dulls  sooner,  drives  harder,  and  does  not  last  so 
long.  A  good  hand-saw  should  spring  regularly  in  proportion  to  its  width  and  gauge ; 
that  is,  the  iwint  should  spring  more  than  the  heel,  and  hence  the  curve  should  not  be 
a  jDerfect  arc  of  a  circle.  If  the  blade  is  too  thick  for  the  size  of  the  teeth,  the  saw  will 
work  stiffly.  If  the  blade  is  not  well,  evenly,  aud  smoothly  ground,  it  will  drive  hard 
and  tend  to  spring.  The  thinner  the  gauge  and  narrower  the  blade,  the  more  need  for 
perfectly  uniform  and  smooth  grinding  ;  the  smoother  and  more  uniform  the  grinding, 
the  thinner  aud  narrower  a  saw  you  can  use.  The  cutting  edge  is  very  often  made  on 
a  convex  curve,  or  with  a  "crown"  or  "breast,"  to  adapt  it  to  tlie  natural  rocking 
motion  of  the  hand  and  arm.  By  holding  the  blade  in  a  good  light,  and  tapping  it, 
you  can  see  if  there  are  imperfections  in  grinding  or  hammering.  Before  buying  a  saw, 
test  it  on  about  the  same  grade  of  work  as  it  is  intended  to  bo  put  to.  It  is  a  mistake 
to  suppose  that  a  saw  which  is  easily  set  and  filed  is  the  best  for  use.  Quite  the  reverse 
is  the  case.  A  saw  that  will  take  a  few  more  minutes  and  a  little  harder  work  to  sharpen 
will  keep  its  edge  and  set  longer  than  one  which  can  be  put  in  order  quickly,  and  it 
will  work  better  in  knots  and  hard  wood. 

Using. — The  first  thing  to  be  considered  is  the  position  of  the  stuff  while  being 
operated  upon.  Board  or  plank  should  be  laid  on  one  or  more  saw-horses  a  in  either  a 
sloping  or  flat  position,  the  saw  being  held  more  or  less  nearly  vertical,  while  the  work- 
man rests  his  right  knee  firmly  on  the  work  to  secure  it.  If  the  stuff  is  more  than  3  in. 
thick  it  should  be  lined  on  both  sides,  and  repeatedly  turned  so  that  the  sawing  proceeds 
from  opposite  sides  alternately;  this  helps  to  ensure  straight  and  regular  cutting.  The 
saw  is  held  firmly  in  the  right  hand  with  the  forefinger  extended  against  the  right  side  of 
the  handle.  The  workman's  eyes  should  look  down  on  both  sides  of  the  saw.  As  the 
work  progresses,  a  wooden  wedge  should  be  driven  into  the  slit  or  "  saw  kerf"  6,  to 
allow  a  free  passage  for  the  saw.  Care  is  needed  not  to  draw  the  tool  too  far  out  of  the 
cut,  or  the  end  will  be  "  crippled  "  by  sticking  it  into  the  wood  when  returning  it  to  the 

p 


210  Cakpentry — Easping  Tools. 

cut.  Grease  should  be  applied  freely  to  lubricate  the  teeth.  Sometimes  the  saw-horse 
is  dispensed  with  and  the  work  is  laid  on  the  bench  and  ht-ld  down  by  the  baud  or  by 
mechaniail  contrivances,  either  with  the  end  of  the  stuff  hanging  over  the  end  of  the 
bench,  or  witli  the  edge  hanging  over  the  side.  Tlie  operator  can  then  stand  erect  at  his 
work  and  can  use  one  or  both  hands.  Continental  workmen  often  use  the  rip-saw  with 
tlie  back  of  the  saw  towards  them ;  they  place  the  work  on  saw-horses  and  commence 
in  the  usual  way,  then  turn  round  and  sit  on  the  work  and  drive  the  saw  before  them, 
using  both  hands. 

For  cutting  wide  tenons,  the  stuff  is  first  gauged  with  a  mortice  gauge  (p.  186),  and 
then  secured  in  a  bencli  vice  in  a  more  or  less  vertical  position.  The  saw  is  first 
applied  in  an  almost  horizontal  position,  the  workman  taking  care  to  adliere  to  the  line 
so  that  the  tenon  may  have  the  proper  size  when  done.  As  soon  as  the  saw  has  entered 
the  line  it  is  inclined  in  such  a  way  as  to  cut  down  to  the  bottom  of  the  mark  on  the 
side  farthest  from  the  operator.  When  that  has  been  reached,  the  stuff  is  reversed,  and 
the  saw  is  worked  in  an  inclined  position  till  the  opposite  shoulder  has  been  reached. 
This  gives  the  limit  of  tlie  cut  at  each  edge,  leaving  a  triangular  piece  uncut  in  the 
middle  of  the  slit,  wliich  is  finally  removed  by  setting  the  work  and  using  the  saw  in  an 
exactly  horizontal  position.  This  facilitates  working  witli  truth  and  accuracy  to  the 
square.  Large  work  is  best  done  with  a  rip-saw;  small,  witli  a  hand-  or  panel-saw. 
The  left  hand  seizes  the  wood  to  steady  the  work  and  the  workman.  The  workman 
makes  a  cut  with  the  grain  of  the  wood,  which  should  always  be  the  first  half  to  be 
performed.  When  the  longitudinal  cuts  have  been  made,  the  cross-cuts  or  shoulders  are 
made  by  laying  the  wood  flat  on  the  bench  against  a  stop. 

For  cross-cutting  timber,  the  hand-saw  is  commonly  used;  the  teeth  are  finer  than 
in  the  rip-saw,  and  are  set  a  little  more  to  give  greater  clearance  in  the  kerf,  as  the  tool 
is  more  liable  to  gain  wlien  cutting  across  tlie  fibres  of  the  wood.  The  saw  is  held  in 
the  right  hand,  the  left  hand  and  left  knee  being  placed  on  the  work  to  steady  it  on  the 
saw-horses.  The  workman  must  proceed  very  cautiously  towards  the  end  of  the  cut, 
and  provide  some  support  (generally  his  left  hand)  for  the  piece  which  is  about  to  be 
detached,  or  it  will  finally